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Basil
19-05-2007, 10:59 PM
r2q1rk1/3bnppp/p3p3/3pP3/2pP2n1/b1P2NN1/P1BB1PPP/1R1Q1RK1 w - - 1 16

17.Bxh7+... Kh8

Now what?

Desmond
19-05-2007, 11:04 PM
Possibly even stronger:

17.h3 Nh6 18.Bxh6 gxh6 19.Nh5

Basil
19-05-2007, 11:06 PM
Possibly even stronger:

17.h3 Nh6 18.Bxh6 gxh6 19.Nh5

I had a look at at that in my mind's eye. I'll check it out a bit later, unless someone else beats me to it. I'll also post the game score for curiosity's sake, unremarkable as it is.

Desmond
19-05-2007, 11:12 PM
Actually, even better appears to be

17.h3 Nh6 18.Bxh6 gxh6 19.Qd2,

when it looks like Black will have to shed decisive material to avoid a mating attack:

19...Ng6 20. Qxh6

with the dual threats of Ng5 and Nh5

20...f5 21.Nh5

and White is winning at least an exchange and probably more.

Aaron Guthrie
20-05-2007, 12:54 AM
17.Bxh7+... Kh8

Now what?I am guessing from your question that something bad happened. Boris' suggestion is good. As regards your explicit question, 18.h3, 18.Ng5 and even 18.Bc2(!) are all very strong.

Capablanca-Fan
20-05-2007, 04:45 AM
How NOT to play the French for Black!

Basil
20-05-2007, 09:37 PM
I am guessing from your question that something bad happened.

Not at all. I've posted the game to allay your fears!

In the game, I fiddled around for what seemed an eternity (not time, quantity of moves). When I posted this, I hadn't had a chance to look at a 'puter for best continuation. I still haven't.

[Event "U/1600 Triple Treat"]
[Date "2007.05.19"]
[Round "2"]
[White "Howard"]
[Black "Kieton Bielby"]
[Result "1-0"]
[WhiteElo "1486"]
[BlackElo "1383"]
[ECO "A40"]

1.d4 e6 2. Nf3 c5 3. e3 Nc6 4. c3 d5 5. Bd3 Nf6 6. Nbd2 Bd6 7. Nf1 a6 8. Bd2 b5 9. Ng3 Bd7 10. O-O c4 11. Bc2 O-O 12. Rc1 b4 13. e4 bxc3 14. bxc3 Ba3 15.Rb1 Ne7 16. e5 Ng4 17. Bxh7+ Kh8 18. Bc2 Qa5 19. Ng5 Nh6 20. Qh5 Be8 21. Qh3 Ba4 22. Bxa4 Qxa4 23. Nf3 Ng8 24. Ne2 Rab8 25. g4 Qc2 26. Rxb8 Rxb8 27. g5 Qg6 28. Nf4 Qh7 29. gxh6 Nxh6 30. Ng5 Qf5 31. Qxf5 exf5 32. Nxd5 Rb5 33. Ne3 f4 34.Nxc4 f6 35. Nxa3 Rb2 36. Nc4 Rxa2 37. e6 Nf5 38. Nf7+ Kg8 39. Bxf4 1-0

Basil
24-05-2007, 11:28 PM
Lordy Lordy. Two Bxh7 games in a week!

White is thinking of 15.Bxh7. With best play from both sides, is the sac sound?

r2q1rk1/1b2bppp/1pn1p3/p2pP3/2pP1P1P/2P2NP1/PPBNQ3/R3K2R w KQ - 1 14

MichaelBaron
24-05-2007, 11:38 PM
It wins by force :D

Basil
24-05-2007, 11:47 PM
Are you sure? ;) Reputation on it? :P

You've got white's position and you're playing Solomon in the Oz Champs - do you play it? Last round, the room is watching and this for the title. How big are your nuggets now? :) Oodles of time on your clock ... hours even! No pressure bwa ha ha ha ha ...

No computers now, people. Do it in your head - and whatever the answer, you'll be better for having done the exercise - promise.

Kevin Bonham
25-05-2007, 12:08 AM
You've got white's position and you're playing Solomon in the Oz Champs - do you play it?

Actually my first reaction was that it was simply an obvious smash. Most likely in a tournament game I would play it without thinking for more than a minute, and then have to spend a lot of time over subsequent moves if the opponent offered unexpected resistance.

Actually in a tournament in such positions such attacks often come off even if not entirely sound anyway.

Basil
25-05-2007, 12:09 AM
Thanks Kevin and Michael. Given what I now know (having analysed at the club and checked on the comp) I would appreciate you guys and others who have checked it on a comp not to spill anything beyond what you have analysed in your heads.

Just yet, anyway. Perhaps in a few days. Thanks. I'd be very interested to see what others of 2000+ have to say.

BTW I played it in the game and won quickly, but that is not necessarily indicative of the correct answer.

Kevin Bonham
25-05-2007, 12:14 AM
Thanks Kevin and Michael. Given what I now know (having analysed at the club and checked on the comp) I would appreciate you guys and others who have checked it on a comp not to spill anything beyond what you have analysed in your heads.

I've deleted my first post to assist you in your quest, as some of that was computer-checked.

What I had in my head was basically the following:

Black has to take it or he's lost a pawn for nothing. After Ng5+ he can't take the knight without the queen and rook battery smashing him. He can only play ...Kh6 and with one knight entrenched and another able to move to the scene I don't think he can survive.

Basil
25-05-2007, 12:29 AM
... some of that was computer-checked.
Do you want to put the position into a comp on long thought?! Can you guess which move it recommends? :doh:


Black has to take it or he's lost a pawn for nothing.
A pawn down is not terminal (no chat of GMs converting the smallest + please); because the parameters are about best play, even if black is worse after being a pawn down - assuming Bxh7+ is best! :wall: :P

Basil
25-05-2007, 12:50 AM
It would be good if new readers to this thread can put their thoughts (not necessarily analysis) on paper instead of just waiting to see how it pans out.

I'd appreciate that and would find your thoughts interesting.

Kevin Bonham
25-05-2007, 01:19 AM
A pawn down is not terminal (no chat of GMs converting the smallest + please); because the parameters are about best play, even if black is worse after being a pawn down - assuming Bxh7+ is best! :wall: :P

I haven't investigated whether not taking it is best play. It's sufficient for the purposes of the original question to note that Black is a pawn down with less than no compensation if the bishop is not taken.

Aaron Guthrie
25-05-2007, 01:37 AM
Lordy Lordy. Two Bxh7 games in a week!

White is thinking of 15.Bxh7. With best play from both sides, is the sac sound?

r2q1rk1/1b2bppp/1pn1p3/p2pP3/2pP1P1P/2P2NP1/PPBNQ3/R3K2R w KQ - 1 1415.Bxh7+ if not take clearly the position is better than a move ago for white (and if you really want to think about not take, 16.Qh5!), so,

15...Kxh7+ 16.Ng5+, 16...Kh6 or 16...Kg8 or 16...Bxg5,

16...Bxg5 17.hxg5+ Kg8 18.Qh5 f6 19.g6 ++--

16...Kg8 17.Qh5 Re8 18.Qxf7+ Kh8 19.Nxe6 Bf8 20.Qh5+ ++--

16...Kh6- 17.Qg4, or 17.h5!? or 17.Nf3 or 17.f5

17. f5 g6 18.h5! ++--

I am leaving it there cause I canna be bothered right now calculating more, not because I am sure that f5 wins like that.

ETA-like everyone else that has commented, it just looks like Bxh7+ must win, so the calculation is just for calculation's sake.

ETA2-Qh5 doesn't really work I guess :)

Basil
25-05-2007, 02:00 AM
I haven't investigated whether not taking it is best play. It's sufficient for the purposes of the original question...
That's a fair comment, Kevin. Thanks. So, you support Bxh7. Good-o
Now, have you plugged the starting position into a deep thought comp! :wall: (the wall is not for you)


that Black is a pawn down with less than no compensation if the bishop is not taken
But as I have said, prudent if not recapturing the bishop is the difference between mate and survival.

And thanks for your efforts, Aaron.

Capablanca-Fan
25-05-2007, 05:00 AM
Black has to take it or he's lost a pawn for nothing. After Ng5+ he can't take the knight without the queen and rook battery smashing him. He can only play ...Kh6 and with one knight entrenched and another able to move to the scene I don't think he can survive.

But what can White get to the scene? Compare Russell John Dive vs Jonathan D Sarfati Wellington 1988 (http://www.chessgames.com/perl/chessgame?gid=1450743) where 16...Kh6 foiled the attack after an h7 sac (by a knight this time).

Capablanca-Fan
25-05-2007, 05:06 AM
15.Bxh7+ if not take clearly the position is better than a move ago for white (and if you really want to think about not take, 16.Qh5!), so,

15...Kxh7+ 16.Ng5+ Kh6- 17.Qg4, or 17.h5!? or 17.Nf3 or 17.f5

17. f5 g6 18.h5! ++--

What about 17... exf5 first?

Aaron Guthrie
25-05-2007, 05:10 AM
But what can White get to the scene? The knight on d2 via g4 maybe. Qc2 might be a strong move at some point.
What about 17... exf5 first? Yeah the idea of f5 isn't very strong. 17...exf5 18.Qe3 Qe8!

MichaelBaron
25-05-2007, 07:35 AM
Do you want to put the position into a comp on long thought?! Can you guess which move it recommends? :doh:


A pawn down is not terminal (no chat of GMs converting the smallest + please); because the parameters are about best play, even if black is worse after being a pawn down - assuming Bxh7+ is best! :wall: :P


Well, in this case i am afraid being pawn down is terminal because cover to the black king is destroyed so Kh8 is not a satisfactory response to Bxh7.

Black should probably try Kxh7 Ng5+ Kh6...not that it is going to save his day.

Basil
25-05-2007, 03:06 PM
Well, in this case i am afraid being pawn down is terminal because cover to the black king is destroyed so Kh8 is not a satisfactory response to Bxh7.

OK. Thanks. As KB mentioned. So developing and tightening the proposition ... Should white play Bxh7?

MichaelBaron
25-05-2007, 05:01 PM
You sure about this? I am coming up with nothing special for white.
:doh: how about bringing more pieces into attack?

Garvinator
25-05-2007, 05:54 PM
Hi Garv. Please refrain from comp analysis commentary on the board at the mo. My hope is for entirely personal assessment commentary. Thanks. Perhaps even consider modifying your post. Appreciate the consideration in advance.
Done, now MB and yourself should delete your posts :)

Kevin Bonham
25-05-2007, 06:17 PM
But what can White get to the scene?

White doesn't need to get very much there given he can mate the Kh6 with P on h5, N on g5, N on g4 in the absence of any attempt by Black to stop this. The question is how Black might attempt to do this without opening himself up further.


Compare Russell John Dive vs Jonathan D Sarfati Wellington 1988 (http://www.chessgames.com/perl/chessgame?gid=1450743) where 16...Kh6 foiled the attack after an h7 sac (by a knight this time).

White could have played 16.Qh5+ but after ...Kg8 17.e5 Rf5 (best) 18.Bxf5 exf5 the two bishops look better than the rook to me, although the position is fairly messy.

Capablanca-Fan
26-05-2007, 12:28 AM
White doesn't need to get very much there given he can mate the Kh6 with P on h5, N on g5, N on g4 in the absence of any attempt by Black to stop this. The question is how Black might attempt to do this without opening himself up further.

Indeed, White's big advantage is Black's difficulty in unravelling. ...g6 allows h5. But as earlier, f5 helps Black by allowing ...exf5 then g6. So White's best might be Nf1 with the idea of Ne3-g4. Black needs to play something like ...Qe8, g6, Rh8.


White could have played 16.Qh5+ but after ...Kg8 17.e5 Rf5 (best) 18.Bxf5 exf5 the two bishops look better than the rook to me, although the position is fairly messy.

I agree; this would have been much better for White than the game. It may have been better for Black to play 15... Rf7.

Basil
26-05-2007, 12:34 AM
White doesn't need to get very much there given he can mate the ...Indeed, White's big advantage is Black's difficulty in unravelling...

Aha! Really! :P

I'd offer that once black finds the correct initial response or two ... it is white {raises finger a la STML avatar} who needs to sink into deep thought and has to ensure {if he can} he can justify the plan which looked so obviously killing but a few moves earlier.

How many eggs would you like on your face, Mr White, one or two? ;)

Capablanca-Fan
26-05-2007, 12:56 AM
Aha! Really! :P

I'd offer that once black finds the correct initial response or two ... it is white {raises finger a la STML avatar} who needs to sink into deep thought and has to ensure {if he can} he can justify the plan which looked so obviously killing but a few moves earlier.

How many eggs would you like on your face, Mr White, one or two? ;)

Bxh7+ seems to be more of an intuitive sac, although White should calculate Bxh7+ Kxh7; Ng5+ Kh6; Nf1 Qe8; Ne3 g6; h5 Rh8 and a few other lines. Alternatively, White could build up more slowly, since Black has played the French very poorly (...c4 slows his play counterplay too much).

Basil
26-05-2007, 01:10 AM
... since Black has played the French very poorly
At our level, who knows how the position was reached ! ;) :eek: :rolleyes:

I'll post the game score later, as well. And it weren't no French!

Basil
26-05-2007, 09:27 PM
OK thanks for your contributions so far. How about this for a proposition? White plays Bxh7+ and loses or draws (with best play for both sides)? Ha!

r2q1rk1/1b2bppp/1pn1p3/p2pP3/2pP1P1P/2P2NP1/PPBNQ3/R3K2R w KQ - 1 14

Desmond
26-05-2007, 09:33 PM
same position? :hmm:

Basil
26-05-2007, 09:53 PM
same position? :hmm:

Same position. But not "Should white play it?", but "Would you believe he's stuffed if he does! :eek:"?

Aaron Guthrie
26-05-2007, 10:03 PM
Same position. But not "Should white play it?", but "Would you believe he's stuffed if he does! :eek:"?No, I wouldn't.

Kevin Bonham
26-05-2007, 10:09 PM
OK thanks for your contributions so far. How about this for a proposition? White plays Bxh7+ and loses or draws (with best play for both sides)? Ha!

Righto, enough of this little game. I hereby give 24 hrs notice of my intention to post computer-assisted analysis tomorrow night, possibly sometime between the Dawkins thingy and the Monaco Grand Prix. :lol:

Basil
26-05-2007, 10:11 PM
http://frogstar.soylentgeek.com/wav/silly1.wav

Look forward to it!

Aaron Guthrie
26-05-2007, 10:19 PM
So are we free to post comp analysis then?

Also I encourage Gunner to post his reasons for thinking that Bxh7+ is possibly even bad.

Desmond
26-05-2007, 10:31 PM
If White has a guaranteed draw as you suggest Howard, then that might be justification enough to take on h7.

Basil
26-05-2007, 10:36 PM
So are we free to post comp analysis then?
Yes, post away. We're all friends here! (Thanks for checking)


Also I encourage Gunner to post his reasons for thinking that Bxh7+ is possibly even bad.
I will not be encouraged!

OK, the real answer(s) is/ are
1. The reasons why Bxh7 could be trappy are too numerous; suffice to say the onus is one white to actually prove something on account of being a bishop down.
2. It is clear already that some variations lose.
3. I don't have the full analysis (due to its complexity), but would welcome seeing (and assessing) the best of the rest! :P
4. I say again (officially here for the first time) that the position is much much much harder than at at first blush - which has been worthwhile in its own right, I hope.
5. I hope to illustrate that the slightest error from white is curtains against strong play.
6. Not doing so has kept Kevin mildy disgruntled for at least 24 hours already ;)
7. Re: Tactical opportunities: If black finds Kh6 quickly and strongish players would, then it is at least white who has the majority thinking to do - big time!

Basil
26-05-2007, 10:37 PM
If White has a guaranteed draw as you suggest Howard, then that might be justification enough to take on h7.
Surely not if white is foregoing an otherwise superior position such as the simple Ng5? (All other things being equal, viz player sttrength, time, both sides playing for a genuine win etc.)

Desmond
26-05-2007, 10:44 PM
Surely not if white is foregoing an otherwise superior position such as the simple Ng5? (All other things being equal, viz player sttrength, time, both sides playing for a genuine win etc.)I can't see a clear win coming from Ng5. All things being equal, the player with his king on h6 usually loses ;)

Basil
26-05-2007, 10:51 PM
I can't see a clear win coming from Ng5.
I believe that you can't. I can't either. But it might be objectively best, taking a good position and making it better.


All things being equal, the player with his king on h6 usually loses ;)
But we're talking about this position. It's only the other factors being equal, not the moves. Do you care to put your nug ... I mean make an assessment of the position like the other good fellows, including myself [we all said take ... take ... take ...] (prior to computer assessment)?

Aaron Guthrie
26-05-2007, 10:54 PM
Yes, post away. We're all friends here! (Thanks for checking)Here is some analysis, not complete at all, and not with clear evaluations from me.

1. Bxh7+ Kxh7 2. Ng5+ Kh6 3.Ndf3 Qd7 (3...Qe8!?) 4.Qc2

A) 4...g6 5.h5 Kg7 6.Nxf7!? [6.hg6 Rh8 7.Rh7+ Rxh7 8.gh7 b5 9.Qh2 Bxg5 10.Nxg5 b4- and it is not clear to me white can actually break through][6.g4!?] 6...gh5 7.Nfg5 Rh8 8.g4-With strong attack

B) 4.Nh2 g6 [4...f5 5.ef6 gf6 6.Ng4+ Kg7 7.Nxe6+ Kh8 8.Nxf8 Rxf8 9.Ne3 looks good to me] 5.h5 Bxg5+!? [5...Kg7 6.Nxf7!?] 6.fg5+ Kg7


1. The reasons why Bxh7 could be trappy are too numerous; suffice to say the onus is one white to actually prove something on account of being a bishop down.My attitude is that Black has to prove that he can allow a sacrifice by me! (i.e. I am a bishop down, so my opponent has to prove he can allow that ;))

2. It is clear already that some variations lose.For Black!;) But really I see quite a few interesting lines, I don't see a lot to be scared of from Whites point of view.

4. I say again (officially here for the first time) that the position is much much much harder than at at first blush - which has been worthwhile in its own right, I hope.Yep there is more to it than is obvious.

5. I hope to illustrate that the slightest error from white is curtains against strong play.And if White plays all the right moves, Black can make the slightest error and it won't be curtains?

Desmond
26-05-2007, 11:02 PM
But we're talking about this position. It's only the other factors being equal, not the moves. yep, and that taken into account, the side with a mating attack having made a modest material investment would usually win.

Do you care to put your nug ... I mean make an assessment of the position like the other good fellows, including myself [we all said take ... take ... take ...] (prior to computer assessment)?1.Bxh7 Kxh7 (1...Kh8 2.Ng5 g6 (else 3.Qh5) 3.h5 looks crushing) 2.Ng5+ Kh6 3.Nf1 going to Nf1-e3-g4 looks quite pleasant for White. Perhaps if you put Rybka on it for a few hours it will find a defense, but I would risk losing OTB with a sac like this.

or

1. Ng5 h6 2.Qh5 Qd7 and I'm thinking White will have to sac here to open lines sooner or later anyway.

Basil
26-05-2007, 11:03 PM
Here is some analysis, not complete at all, and not with clear evaluations from me.
Thanks mate.


A) With strong attack
I'll check it. Nothing worse than a strong attack that loses :P


B)My attitude is that Black has to prove that he can allow a sacrifice by me!
Au contraire, mon highly rated ami. It is black who is saying 'bring it on sucka ... looks tasty doesn't it .... yummo ... see who burps first


And if White plays all the right moves, Black can make the slightest error and it won't be curtains?
For sure. Tricky as hell for both. However in the spirit of the proposition (white having all the goodies), it's white (remember it's from my own game with white) whom I want to test.

Igor_Goldenberg
26-05-2007, 11:03 PM
I'll try to imagine it's a tournament game, here is my calculation (without computer or moving the pieces) with the risk to embarass myself:

1.Bxh7+ Kxh7
2.Ng5+

2...Kg8 is obviously bad because of 3.Qh5, so I'll consider only 2...Kg6 and 2...Kh6 that don't look clear.

a) 2...Kg6 should play 3.Ndf3 or 3.Nf1 with the threat of 4.Qc2+. Probably 3.Ndf3 is better, as balck would have to either take on g5 or play f5.
a1)3.Ndf3 Bxg5 4.hg5 Rh8 5.Qc2+ f5 6.exf6+ Kf7 7.0-0-0 and he can't take on f6 because of Rh7+. two pawns and continous attack should be good enough. as we get closer to the target position, I might find something better.
a2) 3.Ndf3 Rh8 4. Qc2+ Kh6 5.Nxf7+ (forking the queen).
a3) 3.Ndf3 Kh6 4. Qc2 and black can't play Rh8 9Nxf7!)
Meanwhile I threat to play 4.Qc2+ f5 and at worst I can play 5.Nxe6 and get an exchange, but after 5.exf6+ Kxf6 there could be something better.

So a) 2...Kg6 seems alright. At worst I should get 2 pawns and a rok vs 2 minor pieces. when we get closer, I am likely to find something better

Let's consider b) 2...Kh6. Here I wont to try Nf1 with the idea Ne3 and Ng4. Can he get his king out of danger?

b1) 3.Nf1 g6 4. h5 Bxg5 5.hxg6+ Kg7 (5...Kxg6 6.Qh5+ Kf5 7.Qh7+ Kg4 8.Qh3+ Kf3 should lead to a mate. i cannot see it now, but I am sure will find it when we get closer to this position) 6.Rh7+ Kh8 (6...Kg6 7.Qh5+ can't see mate, but must be here)7.Rh8+! Kxh8 8.Qh5+ Kg7 9.Qh7#

b2) 3.Nf1 g6 4.h5 Kg7 5.hxg6. Can't take back with the pawn because of Ne6+ forking the queen. Otherwise at least two pawn for a piece with continuous attack. Just noticed that 5...Rh8 can be met with 6.Nf7

There are plenty of other moves, many of them unforced, but I am confident that the threats of Ne3-g4 and Qc2 should give me sufficient attack. Black would have to play f5 (as g6 does not work), giving me an option of R+2p vs 2 minor pieces

Other factors (tournament situation, time, importance of the game, style and strength of the opponent) might influence how much time I'd spend calculating, but most likely I'd play Bxh7+

I am sure analysis, especially with the computer would find a lot more.

Igor_Goldenberg
26-05-2007, 11:07 PM
Just saw the analysis from Mangafragma (probably with the iron help?).
It's intresting that computer consider 2...Kh6 more dangerous and find 3.Ndf3 to be better then Nf1.

did you try 3.Nf1?

Desmond
26-05-2007, 11:08 PM
Wow Igor, you see much more that me. Remind me to play something boring against you ;)

Aaron Guthrie
26-05-2007, 11:09 PM
It is interesting that everyone but me prefers Nf1 to Ndf3

Igor_Goldenberg
26-05-2007, 11:10 PM
1. Ng5 h6 2.Qh5 Qd7 and I'm thinking White will have to sac here to open lines sooner or later anyway.
what about 1...g6. If 2.h5 Bxg5 3.hxg6 can be met with 3...fxg6. I am talking about safest (not necessary best) defence

Igor_Goldenberg
26-05-2007, 11:11 PM
It is interesting that everyone but me prefers Nf1 to Ndf3

Perhaps computer finds a good defence against 3.Nf1 that is too difficult for human to find.

Basil
26-05-2007, 11:12 PM
Before I get into it, I think it's safe to say that everyone partaking in this thread would play it for the reasons you have outlined.

The purpose is not to inflame or belittle or anything along those lines. I find the position very interesting and surprising. I think it is very instructive. I still don't know what the outcome will be. I know I will find it much quicker with multiple heads (being the calibre of you clowns :P ) on the job as opposed to just Captain Patzer.


yep, and that taken into account, the side with a mating attack having made a modest material investment would usually win.
I think we're headed for a mac thing again, so I'm going to ease off. I understand what you're saying. I think we're at cross purposes. Jono & Barry have done enough bashing heads for one season.

How about I summarise by saying "I hope white can indeed find the mating attack to which you refer", OK?


Perhaps if you put Rybka on it for a few hours it will find a defense, but I would risk losing OTB with a sac like this.
So would/ did I. I'm not sure about the Rybka/ few hours thing. You might be interested to know that in my analysis, the comp was taking forever for white to 'prove' the attack. You missed some chat between The Manager and myself last night. Short story is that in one line black took 4 mins to refute white's 17 minute think!


1. Ng5 h6 2.Qh5 Qd7 and I'm thinking White will have to sac here to open lines sooner or later anyway.
I've checked this reasonable deeply with The Manager. From memory, white lost, although a couple moves later h6+ or hxg6 seemed critical for a result.

Basil
26-05-2007, 11:15 PM
Perhaps computer finds a good defence against 3.Nf1 that is too difficult for human to find.
Hi Igor. I think (not sure) white has to find both Nf1 AND Qc2. These moves are both quite slow. IMO, to find AND play these two moves is quite a challenge for white under the circumstances. Would you agree?

Footnote: This position (refuting the sac) can ONLY be played at top level, so I am out of my league and will defer entirely to your and others opinion.

Aaron Guthrie
26-05-2007, 11:15 PM
Just saw the analysis from Mangafragma (probably with the iron help?).Joint effort, both of us making mistakes at points :)

It's intresting that computer consider 2...Kh6 more dangerous and find 3.Ndf3 to be better then Nf1.I started off doing the same thing as you, (see post 17, though I was writing it down as I did it) and my line started with Ndf3, I never actually bothered to check what the computer's preference when I got to the computer analysis part. On checking now, 3 different engines, letting them each get to about 15 ply 2 give Ndf3 and one gives Nf1.

did you try 3.Nf1?I noted it when Jono mentioned it, but because it Ndf3 was my preference and because the knight on f3 is useful for being on f3 in some lines when I was analyzing I never looked at Nf1.

Igor_Goldenberg
26-05-2007, 11:15 PM
Wow Igor, you see much more that me. Remind me to play something boring against you ;)
Thanks. I wasn't trying to exhaust a position, it's too difficult OTB without moving pieces. Mostly tried to establish that I don't burn the bridges with the risk of immediate loss (e.g. piece down without compensation)

Desmond
26-05-2007, 11:16 PM
what about 1...g6. If 2.h5 Bxg5 3.hxg6 can be met with 3...fxg6. I am talking about safest (not necessary best) defence
4.Rxh7 looks good

Basil
26-05-2007, 11:16 PM
I'll try to imagine it's a tournament game, here is my calculation (without computer or moving the pieces) with the risk to embarass myself:
MAXIMUM RESPECT BIG FELLA

That is absolutely the spirit that I was looking for. Thank you.

Aaron Guthrie
26-05-2007, 11:21 PM
MAXIMUM RESPECT BIG FELLA

That is absolutely the spirit that I was looking for. Thank you.Hey I did pretty the same thing at post 17! :)

Igor_Goldenberg
26-05-2007, 11:21 PM
4.Rxh7 looks good 4...Kxh7. Knight on g5 is already taken and g6 pawn guards h5

Igor_Goldenberg
26-05-2007, 11:23 PM
4...Kxh7. Knight on g5 is already taken and g6 pawn guards h5
Whoops. Forgot Bc2 is still alive. 5.Qh5+

Basil
26-05-2007, 11:27 PM
Hey I did pretty the same thing at post 17! :)
Ditto for you too. I thought I had intimated that from our discussions. Apologies. I've really enjoyed your input and espesh yesterday in SB.

That's one of the reasons I'm prepared to overlook Brisbane ;)

Desmond
26-05-2007, 11:32 PM
Thanks. I wasn't trying to exhaust a position, it's too difficult OTB without moving pieces. Mostly tried to establish that I don't burn the bridges with the risk of immediate loss (e.g. piece down without compensation)I agree.

In a 60+10 standard weekender game for example, you can't afford to spend a whole lot of time attempting to solve something like this. If you spend 20 mins (1/3 of you alloted time!) on a move, and then decide not to play it, you are going to get into time trouble.

Basil
26-05-2007, 11:32 PM
Just a reminder, computers are in play for anyone just joining.

Igor_Goldenberg
26-05-2007, 11:34 PM
1. Ng5 is definetely a viable option

a) 1.Ng5 h6 2.Qh5 black cant' improve postion. white threatens 3.Ndf3, then 4.Bh7+ Kh8 5.Nf7+ Rf7 6.Qf7 Kh7 7.Ng5+

b) 1.Ng5 g6 2.h5 Bxg5 3.hxg6
b1) 3...fxg6 4.Rxh7 Rf7 5.Rxf7 Kxf7 6.fxg5 with better postion
b2) 3...hxg6
b21) 4.fg5 Kg7? 5.Rh7+ Kxh7 6.Qh5+ Kg8 (or Kg7 Qh6+) 7.Bxg6 fxg6 8.Qxg6+ Kh8 9.0-0-0. If 4...Qg5, then either 5.0-0-0 or 5.Qh2
b22) 4.Qh2 Bh4 5.gh4 followed by 6.h5 with strong atack or

Basil
26-05-2007, 11:35 PM
I agree.

In a 60+10 standard weekender game for example, you can't afford to spend a whole lot of time attempting to solve something like this. If you spend 20 mins (1/3 of you alloted time!) on a move, and then decide not to play it, you are going to get into time trouble.

I agree. In fact that was exactly my rationale in the game! So white plays it (Bxh7) quickish. Then black quickly guesses that hiding on the back rank loses quickly in many lines so he cometh forth - to the sixth! Not unreasonable. I would - and I'm an idiot! Now, aren't we back to my difficult scenario with the onus on white or have I missed something?

Igor_Goldenberg
26-05-2007, 11:36 PM
Just a reminder, computers are in play for anyone just joining.

I didn't use it (yet:D ).

Aaron Guthrie
26-05-2007, 11:38 PM
1.Ng5 g6 2.h52.Nxh7!? Kxh7 3.h5 Kg7 4.Qg4 or something like that maybe

Basil
26-05-2007, 11:39 PM
I didn't use it (yet:D ).
You have talents we can only dream of. By the way, do you object to just focussing on Bxh7 lines, as that is the line we (mostly) would play and is the subject of the 'controversy'?

Of course whatever comments you make about any lines will be greatly appreciated.

Desmond
26-05-2007, 11:41 PM
I agree. So white plays it (Bxh7) quickish. Then black quickly guesses that hiding on the back rank loses quickly in many lines so he cometh forth - to the sixth! Not unreasonable. I would - and I'm an idiot! Now, aren't we back to my difficult scenario with the onus on white or have I missed something?Have I missed something that the computer analysis will determine whether this is the best OTB move?

Garvinator
26-05-2007, 11:41 PM
1. Bxh7+ Kxh7 2. Ng5+ Kh6 3.Ndf3 Qd7 (3...Qe8!?) 4.Qc2

A) 4...g6 5.h5 Kg7 6.Nxf7!? 6...gh5 7.Nfg5 Rh8 8.g4-With strong attack

B) 4.Nh2 g6 [4...f5 5.ef6 gf6 6.Ng4+ Kg7 7.Nxe6+ Kh8 8.Nxf8 Rxf8 9.Ne3 looks good to me] 5.h5 Bxg5+!? [5...Kg7 6.Nxf7!?] 6.fg5+ Kg7
In Line A, which knight is going to g5 on move 7 for white?

Garvinator
26-05-2007, 11:43 PM
You have talents we can only dream of. By the way, do you object to just focussing on Bxh7 lines, as that is the line we (mostly) would play and is the subject of the 'controversy'?
I will admit that if I couldnt see anything 'concrete' from Bxh7, I would probably just keeping building up my attempted attack, rather than speculate on Bxh7.

Aaron Guthrie
26-05-2007, 11:44 PM
2.Nxh7!? Kxh7 3.h5 Kg7 4.Qg4 or something like that maybeor 4.hg6 intending Bxg6!

Aaron Guthrie
26-05-2007, 11:46 PM
In Line A, which knight is going to g5 on move 7 for white?Good point, the one on f3.

Basil
26-05-2007, 11:48 PM
I will admit that if I couldnt see anything 'concrete' from Bxh7, I would probably just keeping building up my attempted attack, rather than speculate on Bxh7.
Thanks Garv. You're the first to offer that.


Have I missed something that the computer analysis will determine whether this is the best OTB move?
No. I mean that I think it reasonable that some black players would run to the 6th as quickly as white would play Bxh7. If black did run to the 6th, isn't the onus of a) white finding a successful plan, and b) finding it quickly, a nasty combo?

MichaelBaron
26-05-2007, 11:52 PM
This is getting too complicated and i am getting tempted to turn on my silicon brother "Fritz".:hmm:

Bxh7 must be a win! Now as far as supporting my statement with variations is concerned..to be honest i am out of my depth...lines are getting too long and and its getting tough to analyse it without the board. However, i suspect that Nf1 transferring the knight to aid the attack could be the solution:hmm:

Basil
26-05-2007, 11:55 PM
This is getting too complicated and i am getting tempted to turn on my silicon brother "Fritz".:hmm:
Comps are now in play, Mike.

Aaron Guthrie
26-05-2007, 11:57 PM
Not meaning to reply for Boris, but my take on this.

If black did run to the 6th, isn't the onus of a) white finding a successful planTo me the normal Chess situation is that both players are challenging each other to prove their chess opinion, and claiming that they can prove their own opinion. To me it seems the onus is on both!

b) finding it quickly, a nasty combo?You can get more long term compensation for material. Take a look at the mainline of line A from the stuff I submitted for instance. I think White looks good there, but there is no quick nasty combo, just slowly prying open.

Aaron Guthrie
26-05-2007, 11:59 PM
Yet another vote for Nf1 has come in! Strange that there is such a consensus against me.

Desmond
27-05-2007, 12:01 AM
No. I mean that I think it reasonable that some black players would run to the 6th as quickly as white would play Bxh7. If black did run to the 6th, isn't the onus of a) white finding a successful plan, and b) finding it quickly, a nasty combo?I'd say Black's King standing naked against White's whole army while his extra piece is sitting uselessly on b7 is a nasty combo. Why are you asking anyway? Are you going to post your solution or not?

Basil
27-05-2007, 12:03 AM
To me the normal Chess situation is that both players are challenging each other to prove their chess opinion, and claiming that they can prove their own opinion. To me it seems the onus is on both!
Yes it is. For these reasons, I would and did play the sac. We all agreed. That is what white would do IRL. It's all good. We are all agreed. However, it appears to me at least that the heavier onus is now on white once the King has made it to the 6th.


You can get more long term compensation for material. Take a look at the mainline of line A from the stuff I submitted for instance. I think White looks good there, but there is no quick nasty combo, just slowly prying open.
Yes I agree, too. And I agreed with Boris when I said "I understood what he was saying". I'm not trying to be a pinorcle, here.

But would either or both of you agree that given all the preceding, it is white who gets the nasty surprise when things aren't as obvious as first thought? If you don't agree, that's all good too.

I'm certainly not trying to brow-bash an opinion. It's purely an opinion that I would form; viz

-- WTF?
-- where's my win?
-- where's my bishop?
-- why must I lose to idiots like this? :P

Basil
27-05-2007, 12:06 AM
I'd say Black's King standing naked against White's whole army while his extra piece is sitting uselessly on b7 is a nasty combo.
OK I accept that. See above post. I think you have taken this as a challenge that never existed (I say that because you're are asking about my motives, not my opinions). Your assessment is that black is more nervous, and I accept that.


Why are you asking anyway?
To see if anyone shared my opinion expressed in the above post. It is clear no-one shares it to date.


Are you going to post your solution or not?
I don't have a solution, per se. I have looked at many scenarios and can't find a win for white; which is the point of the thread.

Aaron Guthrie
27-05-2007, 12:12 AM
But would either or both of you agree that given all the preceding as taken into evidence, it is white who gets the nasty surprise when things aren't as obvious as first thought? If you don't agree, that's all good too.Being down material doesn't worry me a great deal, so no it wouldn't be a nasty surprise at all. For example see this game- http://chesschat.org/showthread.php?t=2689- where I play the amusing TN dc5, not concerning myself at all with the fact that I am down a bishop and can regain it. Also note how long it takes to prove (beyond ones intuition) compensation.
I'm certainly not trying to brow-bash an opinion. It's purely an opinion that I would form;Fair enough

Garvinator
27-05-2007, 12:13 AM
I am going to let my engine run for a while. The only thing I have established so far is that after 1. Bxh7 Kxh7 2. Ng5 Kh6 3. Ndf3 and now if Qe8 (offered by mangafranga), black gets smashed in quick time. 4. Qc2 g6 5. h5 and engines are not wanting black here.

Basil
27-05-2007, 12:21 AM
Being down material doesn't worry me a great deal, so no it wouldn't be a nasty surprise at all. http://chesschat.org/showthread.php?t=2689
Nice game!


Also note how long it takes to prove (beyond ones intuition) compensation.
Noted and agreed.

This is what Brian is saying, too, which I have also understood from the get go. I'll have to take your word for it (and readily do so) that the game shown was proved. Certainly looks like it at first blush.

I am hoping that white can 'prove' the win in this one.

Aaron Guthrie
27-05-2007, 12:29 AM
I'll have to take your word for it (and readily do so) that the game shown was proved. Certainly looks like it at first blush.Objectively it might not actually be sound, I was really just talking about OTB decision making. If I see something that I think gives compensation, even if it is clear I have to be down a piece for a long time, I am happy to go for that.

Basil
27-05-2007, 12:33 AM
In the interests of
a) narrowing down time, and
b) finding 'the truth' beyond the human factor (which I think we have more than adequately covered with different opinions as the outcome)

I offer this position as the starting point:

r2q1r2/1b2bpp1/1pn1p2k/p2pP1N1/2pP1P1P/2P3P1/PP1NQ3/R3K2R w KQ - 1 1

I have white approximately -.9 (amazingly to me).

Where to from here for white (to move)?

Basil
27-05-2007, 12:37 AM
Objectively it might not actually be sound, I was really just talking about OTB decision making. If I see something that I think gives compensation, even if it is clear I have to be down a piece for a long time, I am happy to go for that.
Absolutely. I agree and I think we're repeating. Your motivation in that game was the same as the motivation in my game (Bxh7). The psychological and initiative advantages you refer to are all at your disposal.

Where I see this example as different (and I appreciate others don't agree) is that, for me, and quite quickly, black stops the rot. He even has time to ignore the attack completely and expand on the queenside!

Garvinator
27-05-2007, 01:00 AM
I notice that no one has mentioned 0-0-0 so far. :hmm: It seems to be all about the knights from others analysis.

Basil
27-05-2007, 01:04 AM
I notice that no one has mentioned 0-0-0 so far. :hmm: It seems to be all about the knights from others analysis.
OK. Apart from the psyche factors at play for white (need to move quickly to stop black unravelling), and concerning best play, do you believe white should at least consider 0-0-0 as a strong and viable option?

Desmond
27-05-2007, 01:08 AM
Not sure of when GG meant, but castling is prolly worth considering as alternative to Bxh7.

Garvinator
27-05-2007, 01:08 AM
OK. Apart from the psyche factors at play for white (need to move quickly to stop black unravelling), and concerning best play, do you believe white should at least consider 0-0-0 as a strong and viable option?
I think there are 'only' three options for white:

1) Ndf3
2) Nf1
3) 0-0-0

The purpose of 0-0-0 so far seems to be quite simple, bring the a1 rook into the action somehow.

Garvinator
27-05-2007, 01:10 AM
Not sure of when GG meant, but castling is prolly worth considering as alternative to Bxh7.
I am dealing with this position alone.

r2q1r2/1b2bpp1/1pn1p2k/p2pP1N1/2pP1P1P/2P3P1/PP1NQ3/R3K2R w KQ - 0 16

Desmond
27-05-2007, 01:26 AM
I think 0-0-0 is a waste of a tempo in that position, and also the R can be ok on a1 if Black actually managed to crack open the Q-side, say with a timely pawn-a3.

Garvinator
27-05-2007, 01:29 AM
I think 0-0-0 is a waste of a tempo in that position, and also the R can be ok on a1 if Black actually managed to crack open the Q-side, say with a timely pawn-a3.
I think it is much more double edged than the two knight moves as it puts the king closer to where black is wanting to counter attack.

That being said, so far I am not getting any worse evals than for the two knight moves. Will check back later with updates.

I am only really looking at 0-0-0 and seeing if there is anything there because everyone else is pouring over the two knight moves.

Basil
27-05-2007, 01:34 AM
I am only really looking at 0-0-0 and seeing if there is anything there because everyone else is pouring over the two knight moves.
I'm not sure if we're pouring ... perhaps more just staring obliquely (and speaking for myself only :))

-- WTF?
-- Where's my bishop?
-- Oh look at the time!
-- Why must I lose to this idiot! :P

I think we'd all appreciate a good Rybka on the front foot forward ideas.

Capablanca-Fan
27-05-2007, 02:12 AM
I will admit that if I couldnt see anything 'concrete' from Bxh7, I would probably just keeping building up my attempted attack, rather than speculate on Bxh7.
Esp. with Igor Goldenberg's straightforward and risk-free alternative of Ng5 then Qh5.

Capablanca-Fan
27-05-2007, 02:17 AM
It is interesting that everyone but me prefers Nf1 to Ndf3
In both cases the N is aiming for g4, but f3 obstructs the Q and h2 the R, while f1-e3 obstructs nothing. Indeed, on Nf1 g6; h5 Kg7; hxg6 Rh8; Nxf7 it means that ...Rxh1 is not check.

Basil
27-05-2007, 02:19 AM
Esp. with Igor Goldenberg's straightforward and risk-free alternative of Ng5 then Qh5.
I was looking to jump on your comment as a possible Johhny-Come-Lately, but I remembered your observation (http://www.chesschat.org/showpost.php?p=155472&postcount=19) only 5 hours after the initial question was posed :cool:

May I ask (as best as you can tell) given the position, as originally posed, would you too (Bruté) have played Bxh7+ for all the (or indeed other) reasons previously stated?

Kevin Bonham
27-05-2007, 02:23 AM
I have white approximately -.9 (amazingly to me).

The problem is that Black's difficulties are so long-term that if you let a computer run even to 15 ply it may not see them. The only way to try to use a computer to analyse such a position successfully is to start keying in some likely moves and following various possible best play lines for some distance. After a while the computer may smell the coffee, or both the human and the computer may miss something.

My current assessment of the position is +/- with best play.

I agree with 1.Bxh7 Kxh7 2.Ng5+ Kh6 as the key line.

I think that 3.Nf1 is now a clear advantage to white. It may not be the only one.

I offer the following lines. Lines evaluated at +1ish have been removed from the early stages of the analysis as these are likely to be even worse for Black than that.

(a) 3...Qe8 4.Qc2! Rh8 5.h5 and Black must make major concessions, eg (i) 5...f5 6.exf6 gxf6 7.Nxe6 Rg8 8.Nc7 and White will be two pawns up, +-
(ii) 5...Nxe5 6.Ne3 Nd3+ (...g6 and White will be nothing down with an attack still raging) 7.Qxd3! and everything but ...g6 gets mated so Black is smashed.

(b) 3...Qd7 4.Ne3 g6 5.h5 Kg7 6.Nxf7 Nxd4 7.Qg4! Rxf7 8.hxg6 +-

(If that doesn't work, analysis of 4.Qc2 may be of interest, but I think it is a draw:

4.Qc2 g6 5.h5 Kg7 6.Nxf7 gxh5 7.Qd1 reaching the following position:

r4r2/1b1qbNk1/1pn1p3/p2pP2p/2pP1P2/2P3P1/PP6/R2QKN1R b - - 1 23

Now:
(i) 7...h4 8.Qg4+ Kxf7 9.Qh5+ Kg8 10.Qg6+ Kh8 11.Qh6+ Kh8 and White has a draw, I can't find better here yet. 9...Kg7 is not so good for Black: 10.gxh4 Rf7 11.Rg1+ Bg5 12.Ne3 Kf8 13.fxg5 Rh7 14.Qg6 Nd8 15.Ng4 Qg7 16.Rf1+ Ke7 17.Qf6+ Qxf6 18.exf6+ and the three passed pawns are too much +-

(ii) 7...Rg8 8.Qxh5 Kf8 9.Nh6 Rg7 10.f5 exf5 11.Nxf5 White will soon recover an exchange and have rook and two passed pawns for two pieces and an exposed king, +/- at the least.

(iii) 7...Qe8 8.Qxh5 Rh8 mass liquidation on h8 with an endgame where white has rook and two pawns (one connected and passed) for two relatively passive bishops, may be some play in this but I think White is much better.)

(c) 3...Qb8 4.Qc2 g6 5.h5 Kg7 6.Nxf7 gxh5 7.Qe2 Qe8 8.Qxh5 Rh8 9.Qxh8+ etc as in (b)4.Qc2 (iii) line above

(d) 3...Qc8 transposes to (c).

Basil
27-05-2007, 02:32 AM
Thanks Kevin. I will have a look at those (all if possible). As you know by now, I argue (and I accept it's not agreed) that while Black's difficulties are indeed long term (as you say), white's are also long-term - the difficulty in proving the sac. Initiative is great ... but in many lines it's dissipating.

Would you be good enough please to consider doing two things:
1) Suggest white's strongest reposnse to the Kh6 position (perhaps you have with Nf1), and
2) Summarise your post above (not technically because of course your appreciated analysis speaks for itself). I'd more appreciate a statement like white will win most variations with play of equal strength, or similar.

I'd like to remind everybody that some players (like Stephen Solomon possibly) defend better than they attack, so I'd note that the initiative, while important, perhaps should not be over-estimated.

Kevin Bonham
27-05-2007, 02:35 AM
Would you be good enough please to consider doing two things:
1) Suggest white's strongest reposnse to the Kh6 position,

Have not looked at the alternative in detail but I think 3.Nf1 is most likely good enough to win.


2) Summarise your post above (not technically because of course your appreciated analysis speaks for itself). I'd more appreciate a statement like white will win most variations with play of equal strength, or similar.

My summary was "My current assessment of the position is +/- with best play." which means the same thing.

By the way I may find improvements in some lines so will edit them into that post as I do so.

Aaron Guthrie
27-05-2007, 02:37 AM
In both cases the N is aiming for g4, but f3 obstructs the Q and h2 the R, while f1-e3 obstructs nothing.With the Knight on f3 White can respond to Bxg5 with Nxg5. White might be able to chuck away the g5 knight in a sac and then replace it with the f3 one. On f1 the knight is more committed that on f3 where it has the option of coming in via g4 or g5. On f1 the knight is only useful once it comes out again.
Indeed, on Nf1 g6; h5 Kg7; hxg6 Rh8; Nxf7 it means that ...Rxh1 is not check.And on Ndf3 g6, h5 kg7, hg6 rh8 then 0-0-0 is might strong.

The point of my original comment was just that I was surprised I was alone in this feeling, not on the merits of the moves.

Basil
27-05-2007, 02:38 AM
Certainly Nf1 looks one of the best. In the interests of genuine discussion, I'd ask the board how many white players feel they would have chosen this as their first move? I wouldn't (clearly there are strength issues at play here).

For all the genuine talk of Black's difficulties in finding moves, I'd argue (from my standpoint of relative weakness) that white's Nf1 is even harder (and therefore more unlikely) to find.

Comments?

Kevin, just read your #101. Thanks.

Basil
27-05-2007, 02:45 AM
The point of my original comment was just that I was surprised I was alone in this feeling
I've felt this way for most of the thread! :uhoh:

Aaron Guthrie
27-05-2007, 02:47 AM
Certainly Nf1 looks one of the best.The analysis looks very convincing to me. +-/++--

Kevin Bonham
27-05-2007, 02:50 AM
3.0-0-0 is rather streaky (there is a counter-sac ...Nb4) but may deserve consideration too.

I guess the point of 3.Nf1 is that White's basic threat against ...Kh6 is to play h5 then get N to g4 mating. It's hard to find much else by way of ideas for white, and 3.Ndf3 looks less strong because the knight goes to a less active square on its second move and potentially gets in the way on both f3 and h2.

Aaron Guthrie
27-05-2007, 02:50 AM
I wouldn't (clearly there are strength issues at play here). Hey I didn't choose it either :P
For all the genuine talk of Black's difficulties in finding moves, I'd argue (from my standpoint of relative weakness) that white's Nf1 is even harder (and therefore more likely) to find.Ndf3 will still cause Black headaches as far as I am concerned. Though Nf1 I will admit is the better move.

Aaron Guthrie
27-05-2007, 02:56 AM
3.0-0-0 is rather streaky (there is a counter-sac ...Nb4) but may deserve consideration too.

I guess the point of 3.Nf1 is that White's basic threat against ...Kh6 is to play h5 then get N to g4 mating. It's hard to find much else by way of ideas for white, and 3.Ndf3 looks less strong because the knight goes to a less active square on its second move and potentially gets in the way on both f3 and h2.There is Qg4 to stop g6 because if g6 then h5 followed by Nxf7

Capablanca-Fan
27-05-2007, 03:26 AM
I was looking to jump on your comment as a possible Johhny-Come-Lately, but I remembered your observation (http://www.chesschat.org/showpost.php?p=155472&postcount=19) only 5 hours after the initial question was posed :cool:

Not even a Jono-come-lately ;)


May I ask (as best as you can tell) given the position, as originally posed, would you too (Bruté) have played Bxh7+ for all the (or indeed other) reasons previously stated?

Probably. It seems that Black's defensive moves are at least as hard to find as White's offensive ones that seem to win. I might well have analysed Ng5 as well and played that instead if it looked like a more straightforward route to a clear advantage.

Desmond
27-05-2007, 10:16 AM
For all the genuine talk of Black's difficulties in finding moves, I'd argue (from my standpoint of relative weakness) that white's Nf1 is even harder (and therefore more unlikely) to find.Just want to add that with the king so exposed it is extremely likely that White will have opportunities to chuck material and force a draw at some point if he choses.

Basil
28-05-2007, 12:03 AM
Thanks for your help everyone. I think it's clear that white can win well in some positions, especially Nf1.

No-one appears to share my conviction that it is easy for white to miss the plan(s) and therefore allow black to unravel. I'll mark that up to my lack of experience.

So, from here

r2q1r2/1b2bpp1/1pn1p2k/p2pP1N1/2pP1P1P/2P3P1/PP1NQ3/R3K2R w KQ - 1 1

White finds Nf1! I doubt very much I would have. I wonder how many weaker players when confronted with this position would have gone on to lose, and or waste time staring at the position

Thanks again.

Desmond
28-05-2007, 12:34 AM
so ... the million HCD question ...

what happened?

Kevin Bonham
28-05-2007, 12:40 AM
No-one appears to share my conviction that it is easy for white to miss the plan(s) and therefore allow black to unravel. I'll mark that up to my lack of experience.

No, I think it depends on the level of play.

At GM level White would almost certainly win this.
At 2000 level White has better chances, but a significant chance of missing the best line and going wrong. Also it's possible a conservative White would wimp out and not play the sac at all, reasoning that the position is a good one anyway and there is no need to take risks.
At 1600 level the more passive White player will certainly wimp out, while the more aggressive one will play the sac but is as likely as not to mess up the follow-up - anything could happen.

Basil
28-05-2007, 12:47 AM
At 1600 level the more passive White player will certainly wimp out, while the more aggressive one will play the sac but is as likely as not to mess up the follow-up - anything could happen.
I think many white 1600s would play Bxh7 and then stumble against the Kh6 defence. I probably would (even if black just bumbled at the same level). I still believe (for me) it is harder for white to break through than for black to defend - I mean seriously Nf1!! :eek: :P

Garvinator
28-05-2007, 12:51 AM
so ... the million HCD question ...

what happened?
Gunner played the Bxh7 and the game was over a few minutes later ;)

Desmond
28-05-2007, 12:53 AM
what was the rest of the game continuation :wall:

Basil
28-05-2007, 12:56 AM
so ... the million HCD question ...

what happened?

No giggling at 19 where g6 nailed it immediately, thanks! :P

I saw 19.g6 but in all the kerfuffle forgot about the mate on the back rank! Chess blindness focussed only on a lateral rook movement allowing wiggle room, which I decided to stop with a pawn front (g6 to follow after the text) because I mistakenly thought the king was going to e7.

Not a mistake I've made before or hopefully again. The whole game took about 12 minutes on my clock.

[Event "Tal Memorial"]
[Site "BCC"]
[Date "2007.05.24"]
[Round "4"]
[White "Howard"]
[Black "David Cigel"]
[Result "1-0"]
[WhiteElo "1486"]
[BlackElo "1230"]
[ECO "A45"]

1. d4 Nf6 2. Bg5 e6 3. e4 Be7 4. Bxf6 Bxf6 5. f4 O-O 6. Nf3 b6 7. Nbd2 Bb7 8.
Bd3 Bh4+ 9. g3 Be7 10. Qe2 d5 11. e5 c5 12. c3 c4 13. Bc2 a5 14. h4 Nc6 15.
Bxh7+ Kxh7 16. Ng5+ Bxg5 17. hxg5+ Kg8 18. Qh5 f6 19. exf6 Qe8 20. Qh7+ Kf7 21.
Qxg7# 1-0

Desmond
28-05-2007, 01:10 AM
What the...? I thought the whole point of the thread was that you lost the game. Doesn't this just confirm what most were saying all along; that the defender would probably stuff it up sooner or later.

Aaron Guthrie
28-05-2007, 01:11 AM
[Event "Tal Memorial"]I guess the wrong tourney name?

Basil
28-05-2007, 01:24 AM
What the...? I thought the whole point of the thread was that you lost the game.

No. I mentioned it early (http://www.chesschat.org/showpost.php?p=155445&postcount=12) and elsewhere, I think.


Doesn't this just confirm what most were saying all along; that the defender would probably stuff it up sooner or later.
No, the game doesn't illustrate any of the Kh6 ideas.

I am saying that I would have likely stuffed up against Kh6 ideas. I appreciate you and others wouldn't.

Garvinator
28-05-2007, 01:29 AM
I knew the game finished quickly after Ng5, but I never suspected that David actually took the knight :eek: :doh:

Kevin Bonham
28-05-2007, 02:02 AM
Doesn't this just confirm what most were saying all along; that the defender would probably stuff it up sooner or later.

A 1200s defender might do something silly like take the knight opening the file to a massive attack. A strong defender definitely wouldn't do that.

Capablanca-Fan
28-05-2007, 03:11 AM
No, I think it depends on the level of play.

At GM level White would almost certainly win this.

I agree. They would be able to calculate a lot of the lines in your post #101. They would certainly be able to reach the point of knowing they could bale out with perpetual or reach at least two pawns and attack for piece. Then they could safely play the line and hope that they can find something more when they reach this point.

A lot of top players praise sacs more when they can't calculate them to a forced win.


At 1600 level the more passive White player will certainly wimp out, while the more aggressive one will play the sac but is as likely as not to mess up the follow-up - anything could happen.

And at that level, the defense is likely to be weak, e.g not consider Kh6. Of course, don't count on them being weak enough to take on g5, unless it's your birthday, because that really is just too much to hope for ... ;)

Capablanca-Fan
28-05-2007, 03:49 AM
[Event "Tal Memorial"]
[Site "BCC"]
[Date "2007.05.24"]
[Round "4"]
[White "Howard"]
[Black "David Cigel"]
[Result "1-0"]
[WhiteElo "1486"]
[BlackElo "1230"]
[ECO "A45"]

1. d4 Nf6 2. Bg5 e6 3. e4 Be7 4. Bxf6 Bxf6

I know Tromp players hate their Bs ;), but must you exchange? 4. Nc3 Nxe4 5. Bxe7 Nxc3 6. Bxd8 Nxd1 7. Bxc7 Nxb2 8. Bd6 seems like good play for the P, or 4. Bd3.


5. f4 O-O

5. f4 looks loosening. Black should play 5...c5 to attack White's broad P front, followed by a timely Qb6.


6. Nf3 b6 7. Nbd2 Bb7

Black might have gone into a French then played Ba6 to exchange White's attacking B.


8. Bd3 Bh4+ 9. g3 Be7

Wasting more time. Karpov long ago said it was a myth that time wasn't important in a closed position; it is just less important than in an open one.


10. Qe2 d5 11. e5 c5 12. c3 c4

This is horrible, drastically slowing down any counterplay. But Black's previous play has been far too automatic, merely developing when attacking White's centre was a priority. Black has also made it hard to attack the pawn chain from the other direction with ...f6, because his e-pawn lacks cover. And his K would probably be safer anywhere but on the K-side.


13. Bc2 a5 14. h4 Nc6 15. Bxh7+ Kxh7 16. Ng5+ Bxg5

Appalling.


17. hxg5+ Kg8 18. Qh5 f6 19. exf6 Qe8

As you say, 19. g6 was quicker.


20. Qh7+ Kf7 21. Qxg7# 1-0

Basil
28-05-2007, 03:02 PM
Appalling.

This is signature material! I'd strongly recommend you adopt it for a week. After then I think I shall have it for myself.

Thanks for the brief analysis on a brief game. Not only do I agree with it ('cept the bishop part ;)), I think I even understand it.

Yes, 12...c4 was 'orrible, where the tension should have been left in place.

Basil
21-10-2007, 10:04 PM
Here we go again. To 12.Bxh7+ or not to 12.Bxh7+? (against best play).

rn3rk1/pbqp1ppp/1p2p3/2b1P3/5P2/3B1N2/PPPNQ1PP/R3K2R w KQ - 2 11

Kevin Bonham
21-10-2007, 10:16 PM
Hell yeah! Because white has a pawn planted on e5 Black has no ...f5 defence, he also has no kingside defenders, and therefore his king cannot survive on g6 or h6. He will have to go back to g8 then move his rook, and his kingside pawns will all be eaten leaving him with just piece for three pawns and a very weak king

Time taken to determine the above (in white): <2 minutes
Computer use: none.
Relevant chapter of Vukovic read in last three months: yep!

Aaron Guthrie
21-10-2007, 10:55 PM
Here we go again. To 12.Bxh7+ or not to 12.Bxh7+? (against best play).Take, of course. Where is the complication?

Basil
21-10-2007, 10:57 PM
Take, of course.Why?


Where is the complication?
I don't know.

Aaron Guthrie
21-10-2007, 11:03 PM
Why?Cause it wins. Kevin covers it pretty well. Kg6 or h6, then White plays Qd3-Qh3. Kg8, white plays Qh5, wins the f7 pawn, g7 pawn if that is best, and then finds the way to win. It is a pretty damn good version of a Bxh7 sac.
I don't know.If there is no complicating factor, it just wins.

edit-I hid the analysis.

CameronD
21-10-2007, 11:07 PM
This is a good refresher course for me as I've recently gone through powerplay I by daniel King which has around 8-10 chapters on the greak gift.

After 3 minutes of analysis, the following lines occurs

1. Bxh7+ Kxh7 2. Ng5+ Kg8 3. Qh5 Rd8 (Re8 loses the rook) 4. Qxf7+ Kh8 5. Qh5+ Kg8 6. Qh7+ Kf8 7. Qh8+ Ke7 8. Qxg7+ Ke8 9. Qf7# 1-0

working out King forward, return in a minute.

1. Bxh7+ Kxh7 2. Ng5+ Kg6 3. Qd3+ f5 (3... Kh6 4. Qh3+ Kg6 5. Qh7#) 4. Qh3 1-0

that's another 3 minutes... now to work out Kh7

1. Bxh7+ Kxh7 2. Ng5+ Kh6 3. Qd3 Rh8 (3... f5 4. Qh3+ Kg6 5. Qh7#) (3... g6 4.
Qh3+ Kg7 5. Qh7#) 4. Nxf7+ Kh5 5. Qh3+ Kg6 6. Nxh8# 1-0

And that took only 3 minutes as well. Absolutely no computer or book assistence.
I'm only 1347 and I found that easy gunner... good refresher though!!!

Kevin Bonham
21-10-2007, 11:19 PM
...Rc8 is better than ...Rd8 in Cameron's line but Black is smashed after 15.Qxf7+ Kh8 16.Qh5+ Kg8 17.Qh7+ Kf8 18.Qh8+ Ke7 19.Qxg7+ Ke8 20.Qg6+ etc - after White drives the king to d8 then plays Rd1 it's all going to soon be far too much.

Basil
21-10-2007, 11:27 PM
I'll ask at this (late) juncture that comps not be used (forgot) and that players consider the best response of black, which I offer (as a 1500 player without computer checking) is king coming forward. I'm not suggesting the sac is sound or otherwise (against best defence).

FWIW, I had the white pieces in this game at the Brisbane Club Champs last week. I chose not to disclose what happened next just yet :eek:

Kevin Bonham
21-10-2007, 11:30 PM
The best response for Black is 12...Resigns. :lol:

(Actually, at club level, not really. White might goof it.)

Basil
21-10-2007, 11:32 PM
White might goof it.
:uhoh:

Aaron Guthrie
21-10-2007, 11:33 PM
I'll ask at this (late) juncture that comps not be used (forgot) and that players consider the best response of black, which I offer (as a 1500 player without computer checking) is king coming forward.But it has been considered by all commentators.

CameronD
21-10-2007, 11:34 PM
A lot of people (<1500) wouldn't know to take the f pawn first... or have my patience to work through every possible combination before playing Bxh7

Aaron Guthrie
21-10-2007, 11:37 PM
I don't follow Aaron. Are you referring to the lateness of the computer request? The suggestion that king coming forward is best?Did you not just suggest that people consider the best response, and that the best response is king coming forward?

Capablanca-Fan
21-10-2007, 11:39 PM
Pretty good effort, Cameron.

A more pertinent question, however, is how did White get such a terrific attacking lineup from such an antipositional opening as the Tromp? :hmm:

Aaron Guthrie
21-10-2007, 11:44 PM
Aaron, sorry. I really don't follow. I'm going to delete my posts on this side issue as I appear to have clogged the thread. Perhaps you could just make a clear all encompassing statement - that should fix me up - thanks.It seems to me that you are asking us to consider Kh6/Kg6. But this has been considered by all that commentated. So I don't quite understand why you are asking for this to be done, when it already has been.

Aaron Guthrie
21-10-2007, 11:53 PM
Right. I understand what you're saying now. The confusion arose because I had just seen Kevin fairly briefly dismiss it, and your subsequent saying that Kevin's summary covered it. I didn't think people had spent sufficient time on that line. No probs. Deleting all posts relating to this in a little while.I added some moves in white after that.
Please also bear in mind that others will be reading the thread and also my request at a later date.Indeed.

Basil
21-10-2007, 11:56 PM
A more pertinent question, however, is how did White get such a terrific attacking lineup from such an antipositional opening as the Tromp? :hmm:
I get this from time to time against weaker players because, I think:
a) they are a little confused by the very early awkward (to them) concept of off-loading a bishop
b) they suffer from what I am struggling to overcome and have noted here recently; and that is the art of remaining active. In this particular game, ...c5 came about 5 days too late
c) entirely and unnecessarily forgetting king safety (sense of danger).

I certainly wasn't playing for, or expecting this position, but hey that's what I was given ;)

ElevatorEscapee
22-10-2007, 08:39 PM
Sometimes a sacrifice is only justified when accepted and can be refuted simply by refusing it. (Which seems against the laws of chess logic).

If by playing Kh8 in response to the Bxh7+ sac, Black might be able to survive in the short term, even if a pawn down, then the long term endgame considerations must also be brought into the mind of the sacrificer. :)

In the position posted by Mr Gunner, it may well be that Black gets crushed easily after Kh8. However, the person playing the sacrifice must bear in mind that he may not necessarily have a forced, crushing position/mating attack, and only emerges a pawn ahead (which at lower club level, does not always crystalize into a decisive advantage).

I am reminded of a story in a book by Kotov, which tells of a game between Keres and Smyslov... Keres thought long and hard at the position, and eventually played a sacrifice. Smyslov responded quickly by declining the sacrifice. When asked later on why he didn't accept it, he simply said something along the lines of "if he thought that long and hard about it, it had to be justified! I didn't need to waste any time thinking of how to accept it and survive, I merely had to think of the best way to decline it!". :lol:

Smyslov was to later win the game, due in no small part to his advantage on time.

Interesting also was the analysis posted following the position posted by Mr Gunner, not one person mentioned the analysis of the option of declining the sacrifice with Kh8. :)

Now, I am sure someone will be able post some analysis, after declining the sac that proves White still has a decisive advantage... (My personal "chess instinct" tells me that White is winning just by playing the sacrifice...) I just find it an interesting insight into the minds of chess players that analysis of declining the Greek Gift sac wasn't considered. :)

Basil
22-10-2007, 08:41 PM
Great post.

Which reminds me - I must post the rest of the game just so everyone can LTAO at the sheer volume of mating attacks I eeer ... declined to pursue :lol:

Aaron Guthrie
22-10-2007, 08:48 PM
I just find it an interesting insight into the minds of chess players that analysis of declining the Greek Gift sac wasn't considered. :)I didn't mention the option, but I did consider it.

CameronD
22-10-2007, 08:56 PM
The question was wheather to play Bxh7, not whats the best defence. Kh8 justifies the sacrifice. The real problem for black is that all of her pieces are shoved in the corner doing nothing. I doubt that Kh8 works anyway. White could always retreat the bishop gaining a pawn without compensation which justify the proposed sacrifice (remember that Kh8 doesn't gain black an advantage.

Gone through some Kh8 lines and cant find a defence for black... though I'll leave that open to higher rated and better players here.


1. Bxh7+ {0} Kh8 2. Ng5 g6 (2... d6 3. Qh5 g6 4. Bxg6+ Kg7 5. Qh7#) (2... f6 3.
Qh5 fxg5 4. Bg6+ Kg8 5. Qh7#) (2... Qd8 3. Qh5) (2... Be7 3. Qh5 Bxg5 4. fxg5)
3. Qg4 f6 (3... Nc6 4. Qh4 Ne7 5. Bxg6+ Kg7 6. Qh7#) (3... Be7 4. Qh3 Bxg5 5.
Bxg6+ Kg7 6. Qh7#) 4. Qh4 d5 5. Bxg6+ Kg8 6. Bh7+ Kg7 1-0

Basil
22-10-2007, 08:58 PM
The question was wheather to play Bxh7, not whats the best defence.
The two must be considered together, because as Manga like to say, the first proposition begs the second! ;)

Aaron Guthrie
22-10-2007, 09:01 PM
The two must be considered together, because as Manga like to say, the first proposition begs the second! ;)Complete rubbish. I like to stick to the "question begging" construction. <---(for GD's benefit) this is a joke (though I do like to say "question begging" rather than "begs the question")

Basil
22-10-2007, 10:16 PM
And now for everyone's delectation, here's the protracted :eek: finish in the hands of a man who clearly didn't know what he was doing. I apologise in advance to all of those whose sensibilities are offended. Chess is indeed an art - regrettably I don't possess it ;)

1. d4 Nf6 2. Bg5 e6 3. e4 Be7 4. Bxf6 Bxf6 5. f4 b6 6. Nf3 Bb7 7. Nbd2 O-O 8.e5 Be7 9. Bd3 c5 10. dxc5 Bxc5 11. Qe2 Qc7 12. Bxh7+ Kxh7 13. Ng5+ Kg6 14. Qd3+ f5 15. Qh3 Qxe5+ 16. fxe5 Kxg5 17. Nf3+ Kg6 18. O-O-O Kf7 19. Kb1 Be7 20. Qh5+ Kg8 21. h4 Bxf3 22. gxf3 f4 23. Rhg1 Rf5 24. Qe8+ Rf8 25. Qxe7 Rf7 26. Qe8+ Rf8 27. Qg6 Rf7 28. h5 Nc6 29. h6 Nxe5 30. Qe4 1-0

Aaron Guthrie
23-10-2007, 04:23 AM
And now for everyone's delectation, here's the protracted :eek: finish in the hands of a man who clearly didn't know what he was doing. I apologise in advance to all of those whose sensibilities are offended. Chess is indeed an art - regrettably I don't possess it ;)Actually looked like a reasonable way to finish things to me. Do you think Black was ever in danger of holding the position (or making any fightback at all)?

Aaron Guthrie
23-10-2007, 04:31 AM
(remember that Kh8 doesn't gain black an advantage.But it can, in similar positions. After Kh8 a g6 move might win the bishop without getting mated, or perhaps the Bh7 actually gets in the way. And retreating the bishop means Black is on move (so if he had a counter-attack, this could refute retreating the Bishop).

In this case one need not consider it for very long (between 1 and 7 seconds I'd say ;)), but I do think it is worth at least being aware of (since I reckon in similar positions it might work).

Basil
23-10-2007, 11:40 AM
Actually looked like a reasonable way to finish things to me.
The box gives my play 2 blunders with ?? after Bxh7+. I prefer your version.


Do you think Black was ever in danger of holding the position (or making any fightback at all)?
Nah! Black was stuffed from the get go ;)

Capablanca-Fan
23-10-2007, 04:51 PM
1. d4 Nf6 2. Bg5 e6 3. e4 Be7 4. Bxf6 Bxf6 5. f4 b6 {one day, someone will find 5... c5, and already Black looks better} 6. Nf3 Bb7 7. Nbd2 O-O 8.e5 Be7 9. Bd3 c5 10. dxc5 Bxc5 11. Qe2 Qc7 {Black should try 11... f6. Black has played too automatically, while White has played logically after the poor start} 12. Bxh7+ {of course! This is even clearer than the last one} 12... Kxh7 13. Ng5+ Kg6 14. Qd3+ f5 15. Qh3 Qxe5+ {desperation} 16. fxe5 Kxg5 17. Nf3+ Kg6 18. O-O-O Kf7 19. Kb1 Be7 20. Qh5+ Kg8 21. h4 Bxf3 22. gxf3 f4 23. Rhg1 Rf5 24. Qe8+ Rf8 25. Qxe7 Rf7 26. Qe8+ Rf8 27. Qg6 Rf7 28. h5 Nc6 29. h6 Nxe5 30. Qe4 1-0

Basil
23-10-2007, 05:04 PM
{one day, someone will find 5... c5, and already Black looks better}

Refer point b) below (from earlier in this thread)
http://www.chesschat.org/showpost.php?p=171628&postcount=142

Kevin Bonham
23-10-2007, 08:39 PM
The box gives my play 2 blunders with ?? after Bxh7+. I prefer your version.

So do I.

The box, not knowing any better, thinks the difference between a move that is +7 and a move that is +4 is a ?? just the same as the difference between +1 and -2.

But for practical purposes, all you have to do is maintain a completely winning position and a move that does that, even if it is less than the most destructive, is not such a serious error.

You did not let the opponent back into the game - I have had many similar wins where I do not put the opponent away in the most destructive possible fashion but because I was always in control that's fine by me.

Basil
24-10-2007, 12:08 AM
So do I.

The box, not knowing any better, thinks the difference between a move that is +7 and a move that is +4 is a ?? just the same as the difference between +1 and -2.

But for practical purposes, all you have to do is maintain a completely winning position and a move that does that, even if it is less than the most destructive, is not such a serious error.

You did not let the opponent back into the game - I have had many similar wins where I do not put the opponent away in the most destructive possible fashion but because I was always in control that's fine by me.
Yes to all of the above. What concerns me (rightfully) is that I missed to two forced mates. In more even positions (or say where counter play was available to the opponent), I need to improve this part of my game.

For instance I saw 25. Rxg7 as an option but didn't play it. I can't recall why. Perhaps it was because I was flitting in and out of the tournament hall observing a CAQ meeting or an inability to calculate to the end (of a fairly short) terminal sequence. Either excuse isn't much chop.

Capablanca-Fan
24-10-2007, 01:02 AM
For instance I saw 25. Rxg7 as an option but didn't play it. I can't recall why. Perhaps it was because I was flitting in and out of the tournament hall observing a CAQ meeting or an inability to calculate to the end (of a fairly short) terminal sequence. Either excuse isn't much chop.
It would have been a nice finish. But really, KB is right. If you find a clear win, then why not play it, rather than look for others? Kotov in Think Like a Grandmaster gives several examples of wins being thrown away in a vain quest for brilliancy instead of simple and effective finishes. So there is no need to beat yourself up for playing the simple 25. Qxe7.

Now, playing Bxf6 and f4 in the opening is a different matter, because 5... c5 would have actually made a difference, unlike 25. Qxe7.

Aaron Guthrie
08-12-2007, 02:57 PM
The sac can also be played on a2, such as I did in this position in a rapid tournament today.r2qr1k1/pp3ppp/2n1bb2/2p5/3pNP2/3P2P1/PPPQ2BP/1K1R2NR w KQ - 2 11

Aaron Guthrie
20-12-2007, 01:12 PM
In the above game (which was from the street chess tournament in Canberra) my opponent played Kc1. I had a look at the acceptance with the computer and it is not as simple as it at first seems. In white- 1...Bxa2+ 2.Kxa2 Nb4+ 3.Kb1 Qa5 4.Nxf6+ gxf6 5. Bd5!

Spiny Norman
20-12-2007, 01:28 PM
Here's my contribution. I've just finished reading through the whole thread again. Very helpful to this mere mortal. In a game last year (60+30, against a player about 300 points stonger than myself) I reached the following position as White. To take, or not to take? I will post my continuation later:

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 9.c3 Bc5 10.Nbd2 0-0
11.Qe2 Nxd2 12.Bxd2 Re8 13.Bc2 Bf8

Aaron Guthrie
20-12-2007, 01:43 PM
To take, or not to take?Looks like a real sacrifice to me this time- 14.Bxh7+ Kxh7 15.Ng5+ Kg8 16.Qh5 Bc5 and now I am not sure if there is a good way to play it, I am guessing Qh8+-Qxg7 is no good, I also suspect that a slow buildup (e.g. a Kh1-f4 type plan) wouldn't work since Black's pieces look reasonably good

Desmond
20-12-2007, 07:55 PM
Don't do it Frosty! 14.Bxh7+ =+ 14.Ng5 += IMO

CameronD
20-12-2007, 10:29 PM
I haven't look at others responses, but a quick look tells me not do so without a lot of consideration as the e6 bishop keeps blacks position sound.

The normal proceedure is...

Bxh7 Kxh7. Ng5+ Kg8. Qh5 Bc5. Qxf7 (which cant be played due to the bishop

Kevin Bonham
20-12-2007, 11:33 PM
The sac may not be all that bad because there may be a way to set up threats involving the bishop coming to g5. But it is very tempting to just play Ng5 instead which cannot possibly be that bad. It might depend on the style more than the strength of my opponent.

CameronD
21-12-2007, 12:01 AM
The sac may not be all that bad because there may be a way to set up threats involving the bishop coming to g5. But it is very tempting to just play Ng5 instead which cannot possibly be that bad. It might depend on the style more than the strength of my opponent.


White seems to have a good game here, why play something crazy like Bxh7. Create a plan and play sensible chess.

In Powerplay 1, which had bishop sac in 5 chapters, the first exam question the answer was to play a sensible move as white had a good game and black could force a draw with correct play against Bxh7 in one line. Very complicated examples on that software, but I got 8/10 correct. I never play to hope that my opponents make an error.

Capablanca-Fan
21-12-2007, 12:32 AM
Looks like a real sacrifice to me this time- 14.Bxh7+ Kxh7 15.Ng5+ Kg8 16.Qh5 Bc5 and now I am not sure if there is a good way to play it, I am guessing Qh8+-Qxg7 is no good, I also suspect that a slow buildup (e.g. a Kh1-f4 type plan) wouldn't work since Black's pieces look reasonably good
Yeah, after Qxg7, Black can play ... Rg8 and beat off the attack. 14. Ng5 gains a good position without risk, with a followup of f4-f5.

Spiny Norman
21-12-2007, 08:54 AM
14.Bxh7+ Kxh7 15.Ng5+ Kg8 16.Qh5 Bc5 and now I am not sure if there is a good way to play it, I am guessing Qh8+-Qxg7 is no good, I also suspect that a slow buildup (e.g. a Kh1-f4 type plan) wouldn't work since Black's pieces look reasonably good
I'll throw something new into the mix here ... as I sat at the board, I calculated and then discarded that line as not being forcing enough. After a couple more minutes thought I came up with a line starting with:

14.Bxh7+ Kxh7 15.Ng5+ Kg6 16.h4 ...

Back over to y'all

Kevin Bonham
21-12-2007, 10:36 AM
I'll throw something new into the mix here ... as I sat at the board, I calculated and then discarded that line as not being forcing enough. After a couple more minutes thought I came up with a line starting with:

14.Bxh7+ Kxh7 15.Ng5+ Kg6 16.h4 ...

...Nxe5 (best as after h5+, white will have to go to h6 running into a very nasty revealed check which recovers the piece for nothing) 17.h5+ Kf6 18.Nh7+ Ke7 19.Qxe5 +/-. White is no longer material down and the black king is still vulnerable.

I think that ...Kg8 is the critical variation. As Jono points out the immediate ...Qh7+-Qh8+-Qxg7 just loses to ...Rg8. However, what if white plays the check on h7, then finds a way to move the knight such that Bg5 can be played? Then h8 is a serious problem.

I'm not convinced there is enough gas in the tank for a forced win (and Ng5 is very strong anyway so why bother) but I do think there are serious practical chances of black losing to the bishop sac as well.

Aaron Guthrie
21-12-2007, 02:40 PM
White seems to have a good game here, why play something crazy like Bxh7.Why play something crazy?!?! Need you even ask?
Create a plan and play sensible chess. Now that is crazy!

Aaron Guthrie
21-12-2007, 02:48 PM
I think that ...Kg8 is the critical variation. As Jono points out the immediate ...Qh7+-Qh8+-Qxg7 just loses to ...Rg8. However, what if white plays the check on h7, then finds a way to move the knight such that Bg5 can be played? Then h8 is a serious problem.Not if while you are winning the opponents queen on d8 you are losing your own on h8.

So, 14.Bxh7+ Kxh7 15.Ng5+ Kg8 16.Qh5 Bc5 17.Qh7+ Kf8 18.Nxe6+!? fxe6 (18... Rxe6? 19.Qh8+ and Bg5+ does win now) and now is there any way through (and is there time for such) with something like Rad1-Rd3 or Kh1-f4-f5?

I'm not convinced there is enough gas in the tank for a forced win (and Ng5 is very strong anyway so why bother) but I do think there are serious practical chances of black losing to the bishop sac as well.There are always practical chances, but what is the objective evaluation?

Kevin Bonham
21-12-2007, 10:07 PM
Not if while you are winning the opponents queen on d8 you are losing your own on h8.

I'm more interested in threatening a mating net by putting the bishop on g5 then playing Qh8 first actually.


So, 14.Bxh7+ Kxh7 15.Ng5+ Kg8 16.Qh5 Bc5 17.Qh7+ Kf8 18.Nxe6+!?

Nxe6+ looks insufficient. g5 must be protected.

18.Nf3's not good enough either as Black just plays ...f6.

The box proposes (in white for the benefit of those still attempting human-only solutions as curiosity has got the better of me again) 18.Rad1! threatening Ne4 which will be immune to capture without black being mated. Only good reply appears to be ...Nxe5 - evaluation appears to give white the options of a draw or a roughly level mess

Spiny Norman
22-12-2007, 10:59 AM
The box proposes (in white for the benefit of those still attempting human-only solutions as curiosity has got the better of me again) 18.Rad1! threatening Ne4 which will be immune to capture without black being mated. Only good reply appears to be ...Nxe5 - evaluation appears to give white the options of a draw or a roughly level mess
That is indeed a very interesting line and quite promising. But I wasn't able to see that far at the board. My thought process ran roughly as follows:

-- I'm playing an opponent who is stronger, so in the absence of a flash of brilliance on my part (or a silly mistake on his part) I'm liable to lose anyway;
-- Bxh7 moves the position from a positional struggle to a tactical one, thus making it more likely that I can accidentally play a brilliance, or induce a mistake from my opponent

I sat there calculating for a few minutes, quite uncertain. A glance at my opponent. He was watching me. I laughed and muttered "Okay, you're on!" and sacced the bishop. Here's how the game ended up:

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6
9.c3 Bc5 10.Nbd2 0-0 11.Qe2 Nxd2 12.Bxd2 Re8 13.Bc2 Bf8 14.Bxh7+?! Kxh7 15.Ng5+ Kg6!?
16.h4! Nxe5 17.h5+ (17.Qxe5 was tempting, because 17...f6?? loses to 18.h5+! Kxh5 19.Qh2+ Kg6 20.Qh7#, but Black has alternatives)
17...Kf5? 18.Qe3?
(18.Nf3 seems to win ... thanks Kevin! ... for example: 18...Nxf3+ (18...Kf6 19.Bg5+ Kf5 20.Qxe5+ Kg4 21.Qg3+ Kxh5 22.Qh4+ Kg6 23.Ne5+ Kf5 24.Qf4#) (18...Bc8 19.g4+ Nxg4 20.Nd4+ Kf6 21.Qf3+ Ke7 22.Nc6+) 19.Qxf3+ Ke5 20.Qf4#)
18...Kf6 19.Nh7+ Ke7 20.Qxe5 Qd6 21.Qxd6+ Kxd6 22.Nxf8 Rxf8
23.f3 c5 24.Bf4+ Kc6 25.h6 gxh6 26.Bxh6 Rg8 27.Be3 Rg6 28.Kf2 a5 29.g4 f5 30.g5 Rh8
31.Rh1 Rgg8 32.Rh6! Rxh6 33.gxh6 Rh8 34.Rg1?! (34.Rh1 is stronger) 34...d4 35.cxd4 cxd4 36.Bxd4 Rxh6 37.a3 Rh4
38.Ke3 f4+ 39.Ke4 Bd5+ 40.Ke5 Bxf3 41.Rg6+ Kb7 42.Rf6 Be2 1/2-1/2

Kevin Bonham
22-12-2007, 11:08 AM
Well done on the draw. Given the rating difference, a good reward for a decision to mix it up.

I am surprised by him playing ...Kg6 and also the very bold looking ...Kf5, but the refutation of the latter is far from obvious. Apparently the exceedingly nifty (in white again) 18.Nf3 wins overwhelmingly.

Spiny Norman
22-12-2007, 11:22 AM
Wow ... yes, it looks like it does ... too hard for me to find though ... I find knight retreats (and retreats generally) probably the toughest moves to visualise.

EDIT: I'll try and edit a few of those lines into the game above ... thanks!

Kevin Bonham
17-05-2008, 11:45 PM
Another instructive position from my ongoing annotation project - indeed one where I have just found that my old "?"s and "!"s were wrong.

Bonham - George, Sandy Bay Club Champs 1999

1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Bd3 d5 6.e5 Nfd7 7.Qe2 Nc6 8.Nxc6 bxc6 9.0-0 Bc5 10.Kh1 0-0 11.Nd2 Re8 12.f4 Bb6 13.Nf3 Rb8 14.Bxh7+ Kxh7 15.Ng5+ Kg6

1. What is the result with correct play after 14.Bxh7 ?

2. What should White play on move 16 and why?

3. What should White not do on move 16 and why?

4. What do you think White did?

5. The game ended on move 72. What was the result?

(Ross and I have had some very sharp games! Another old one I just annotated was drawn by repetition on 19 but not before both players missed crushing forced wins including one in the final position!)

Axiom
17-05-2008, 11:58 PM
Another instructive position from my ongoing annotation project - indeed one where I have just found that my old "?"s and "!"s were wrong.

Bonham - George, Sandy Bay Club Champs 1999

1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Bd3 d5 6.e5 Nfd7 7.Qe2 Nc6 8.Nxc6 bxc6 9.0-0 Bc5 10.Kh1 0-0 11.Nd2 Re8 12.f4 Bb6 13.Nf3 Rb8 14.Bxh7+ Kxh7 15.Ng5+ Kg6

1. What is the result with correct play after 14.Bxh7 ?

2. What should White play on move 16 and why?

3. What should White not do on move 16 and why?

4. What do you think White did?

5. The game ended on move 72. What was the result?

(Ross and I have had some very sharp games! Another old one I just annotated was drawn by repetition on 19 but not before both players missed crushing forced wins including one in the final position!)
1. 1-0
2.f5+ because exf5 Rxf5 Kxf5 Qf3+ if Kxe5 Qf4++
if Kg6 Qxf7+ Kh6 Nxe6+
3.Qd3+ due to f5 exf6 Kxf6 escaping
4.Qd3+
5.Draw

Kevin Bonham
18-05-2008, 12:05 AM
Interesting answers; Ax scores 2/5 (though in one case for the wrong reason) and has the right idea about one of the others.

(I should point out that there are a number of correct answers to Q3, though some are more "correct" than others.)

CameronD
18-05-2008, 12:35 AM
1. draw
2. 1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nf6 5. Bd3 d5 6. e5 Nfd7 7. Qe2 Nc6 8. Nxc6 bxc6 9. O-O Bc5 10. Kh1 O-O 11. Nd2 Re8 12. f4 Bb6 13. Nf3 Rb8 14. Bxh7+ Kxh7 15. Ng5+ Kg6 16. Qd3+ f5 17. Qg3 Qe7 18. Nxe6+ Kh5 ( 18... Kh7 19. Qh3+ Kg8 20. Nxg7 Kxg7 21. Rf3 Kf7 22. Qh7+ Ke6 23. Qg6+ Nf6 24. exf6 Qxf6 25. Re3+ Kd7) 19. Qh3+ Qh4 20. Nxg7+ *

3. 1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nf6 5. Bd3 d5 6. e5
Nfd7 7. Qe2 Nc6 8. Nxc6 bxc6 9. O-O Bc5 10. Kh1 O-O 11. Nd2 Re8 12. f4 Bb6 13. Nf3 Rb8 14. Bxh7+ Kxh7 15. Ng5+ Kg6 16. f5+ exf5 17. Rxf5 Rxe5 18. Rxe5 Nxe5 19. Qxe5 Bc7 *

4. h4

5. 0-1





Another instructive position from my ongoing annotation project - indeed one where I have just found that my old "?"s and "!"s were wrong.

Bonham - George, Sandy Bay Club Champs 1999

1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Bd3 d5 6.e5 Nfd7 7.Qe2 Nc6 8.Nxc6 bxc6 9.0-0 Bc5 10.Kh1 0-0 11.Nd2 Re8 12.f4 Bb6 13.Nf3 Rb8 14.Bxh7+ Kxh7 15.Ng5+ Kg6

1. What is the result with correct play after 14.Bxh7 ?

2. What should White play on move 16 and why?

3. What should White not do on move 16 and why?

4. What do you think White did?

5. The game ended on move 72. What was the result?

(Ross and I have had some very sharp games! Another old one I just annotated was drawn by repetition on 19 but not before both players missed crushing forced wins including one in the final position!)

Kevin Bonham
18-05-2008, 12:52 AM
Cameron also scores 2/5.

One of the 2 is that he provides a correct refutation of Axiom's 16.f5+ and 17.Rxf5 idea, although it is worth noting that there is an even stronger refutation of that line.

Bill Gletsos
18-05-2008, 12:54 AM
1. 1-0
2. Rf3 with threats of Rg3 and discovered check or also Nxe6 if the f pawn moves
3. f5+ due to ef Rxf5 Rh8
4. Qd3
5. 0-1

Kevin Bonham
18-05-2008, 12:55 AM
Bill scores 4/5!

Bill Gletsos
18-05-2008, 12:58 AM
Ok then 4. Qg4

Basil
18-05-2008, 05:41 AM
1. 1-0
2. Qg4
3. any'ish
4. Qd3
5. 1-0

Kevin Bonham
18-05-2008, 01:36 PM
OK, the answers are:

1. 1-0 With best play, this is a smash.

2. 16.Rf3. White is threatening Rg3. If ...f6 then 17.Qd3+! forcing ...f5 then 18.Rg3 and black is lost after, for example ...Qe7 19.Nxe6+ Kh7 20.Qxf5+ Kg8 and now 21.Rxg7+ ends up with white with queen and three passed pawns for rook and piece.

(Also the even stronger 21.Nxg7 allows black to choose between 21...Qxg7 22.Rxg7 Kxg7 23.e6 (black has a rook and two pieces for a queen and four pawns but soon loses further material) or 21...Bf2 22.Nxe8+ Bxg3 23.Qg6+ Kh8 24.Nd6 forcing Qg7 25.Qxg3 and white is four pawns up.)

Black's best response to 16.Rf3 is apparently, of all things, ...Ba6 to disrupt the Qd3 threat, but white can either just say thanks for the bishop, or else play 17.c4! threatening Qc2+ instead.

3.Pretty much anything except 16.Rf3 or 16.g4 (the latter should also win but not as emphatically).

Ax is correct that 16.Qd3+ doesn't work that well because of ...f5 17.exf6 Kxf6 escaping. However looking at lines after 18.Bd2 I now think that white is also winning here! (again not that emphatically.)

Ax's line 16.f5+ exf5 17.Rxf5 can be refuted in many ways but the most destructive is 17...Nf6!! The rook must retreat, the knight is immune to capture and it can also go to e4 to block Qd3+.

4. 16.Qg4? White was needlessly worried about 16.Rf3 f6 having not seen the strength of Qd3+ and therefore decided to set up the discovered check immediately. The problem with this is that after ...f5 17.Qg3 white is not actually threatening anything because with the queen on the g-file instead of the rook, the only thing white is threatening to do on g7 is lose another piece :wall: :wall: :wall:
Instead after 17...Qe7 White has 18.Qh3 Nf6 19.Rf3 Bd7 20.exf6 gxf6 and now 21.Nf7 with a draw or 21.Nh7 Bf2!! 22.Rxf2 Rh8 recovering the piece with approx equality.

Also worth noting that after 16...f5 17.exf6 Nxf6 18.Qh3 white should be able to at some stage get the piece back or pick up a perpetual check.

5. 0-1 White played 16.Qg4? f5 17.Qg3 Qe7 18.Nxe6+? and then after ...Kh7 19.Ng5+ Kh8 20.Qh3 g6! found that he didn't have much of an attack.

Black heroically survived all Swindle attempts and the last adjournment in Hobart chess history (caused by a fire alarm!) and white resigned 52 moves later.

EcoChess
22-10-2008, 03:24 AM
Hi:
If you play 1.Bxh7!?-Kh8 (Kxh7 is bad); 2.Bc2 (2.Ng5?-f5 and your bishop is caught) with idea of h3-Bxh6.
Much better is 1.h3! with idea of Bxh6-Qd2 x h6
http://www.ecochess.com
I see you later

Kevin Bonham
30-01-2009, 12:42 AM
And another old case file just unearthed, this one from 1999:

? - Bonham, State Interclub

1.d4 d5 2.Nf3 Nf6 3.c4 c6 4.cxd5 cxd5 5.Nc3 e6 6.e3 a6 7.a4 Nc6 8.Bd3 Qc7 9.0-0 Bd7 10.Bd2 Rc8 11.Rc1 Qb6 12.b3 Ba3 13.Rb1 Bd6 14.Re1 0-0 15.Rc1 Na5 16.Rb1 Rc7 17.e4 Bb4 18.e5 Bxc3 19.exf6 gxf6 20.Bxh7+ Kxh7 21.Ng5+ Kg6

1. Should white have played 20. Bxh7+? Why/ why not?

2. Should black have taken the bishop? Why/why not?

3. What should white play on move 22?

4. What did white play on move 22?

5. The game ended on move 27. What was the result?

Alexrules01
30-01-2009, 09:43 PM
1. b4! is better

Black loses the knight or Bishop


2. No. 20...Kg7 21.b4 still gives white the edge, but he loses a minor piece in the process, whereas if he played b4 first, he would have kept it

3. Qg5! The only move i believe

4. Seeing as you have asked what did White play, that means it wasn't Qg5.
I will say 22. Nh7?

5. 0-1

Saragossa
01-02-2009, 12:59 AM
1. I wouldn't do it but I think it is semi-justified in the line:
20...Kxh7 21.Qc2+ Kg7-g8-h8 22.Bxc3 leaves white a pawn up but black has some compensation in traps and control of the c-file.

I'll answer more tomorrow. (later today)

Desmond
01-02-2009, 07:49 AM
1. Should white have played 20. Bxh7+? Why/ why not?

2. Should black have taken the bishop? Why/why not?

3. What should white play on move 22?

4. What did white play on move 22?

5. The game ended on move 27. What was the result?
1.As Tony says, 20.b4 is strong. Can't see a refutation to the B sac though, it is probably stronger.

2. From a practical perspective, yes. Make him prove it. Also if 20...Kg7 21.b4 again looks good.

3. 22.Qg4, and the knight is taboo after 22...fxg4 23.Qxg4+ Kh7 24.Re3 decides

4. 22.Qc2+ is interesting because of pins n stuff, but fails. 22... f5 23.Bxc3 Rfc8 and the tempting 24.Bxa5 fails to the simple 24...Qxa5 where black picks up an extra piece.

5. Don't know. Get mated on f6 with a Qg5 by chance?

Kevin Bonham
02-02-2009, 11:35 PM
OK, the "answers" and the way the game continued.

1. Should white have played 20. Bxh7+? Why/ why not?

No, because although the move is sound white has much better. As Alexrules01 points out 20.b4 is strong (it most likely wins piece for pawn) but even stronger is 20.Ne5! Black can't take it without getting mated and is quickly smashed on the kingside.

2. Should black have taken the bishop? Why/why not?

Practically, it's debatable, and the result of the game vindicates taking it to some degree. Objectively, taking loses with best play, which is not especially difficult to see, whereas by not taking (20...Kg7) black is struggling, but down no material (black took a pawn before white took h7) and in some sense in the game. An example line is 20...Kg7 21.b4! Nc4 22.Bxc3 Kxh7 23.Nd2 Rg8 24.Qh5+ Kg7 25.b5; +/- or so, but white still has to actually win it.

3. What should white play on move 22?

22.Qg4 as correctly suggested by Alexrules01. After 22...Bxd2 23.Nxe6+ Bg5 24.Nxf8+ White wins the exchange with continued attack. Black can try 22...f5 23.Qg3 first, but now after 23...Bxd2 24.Nxe6+ only ...Kh5 doesn't get mated, and the loose king makes a very easy target. 22...f5 23.Qg3 Kf6 doesn't work either as 24.Qh4 wins easily.

4. What did white play on move 22?

Alexrules is correct again - 22.Nh7? It's only a good move if black takes it, which he doesn't have to do. Black can blunt white's attack substantially with 22...Rh8 (which I played) but an even better move is ...Rfc8!! which appears to lead to a draw (and to practical winning chances should white miss the point) in the line 23.Qg4+ Kxh7 24.Re3 Bxd2 25.Rh3+ Bh6 (note this defensive theme carefully) 26.Qf4 Kg8 27.Qxh6 Rc1+ 28.Rxc1 Rxc1+ 29.Qxc1

5. The game ended on move 27. What was the result?

0-1. White missed the critical B-d2-h6 defensive maneuver and was simply three pieces down without a mate in sight. Game below with the above variations as sidelines.

1.d4 d5 2.Nf3 Nf6 3.c4 c6 4.cxd5 cxd5 5.Nc3 e6 6.e3 a6 7.a4 Nc6 8.Bd3 Qc7 9.0-0 Bd7 10.Bd2 Rc8 11.Rc1 Qb6 12.b3 Ba3 13.Rb1 Bd6 14.Re1 0-0 15.Rc1 Na5 16.Rb1 Rc7 17.e4 Bb4 18.e5 Bxc3 19.exf6 gxf6 20.Bxh7+ Kxh7 [20...Kg7 21.b4 Nc4 22.Bxc3 Kxh7 23.Nd2 Rg8 24.Qh5+ Kg7 25.b5 axb5 26.Bb4] 21.Ng5+ Kg6 22.Nh7 [22.Qg4 Bxd2 (22...f5 23.Qg3 Bxd2 (23...Kf6 24.Qh4) 24.Nxe6+ Kh5 25.Qh3+) 23.Nxe6+ Bg5 24.Nxf8+] 22...Rh8 [22...Rfc8 23.Qg4+ Kxh7 24.Re3 Bxd2 25.Rh3+ Bh6 26.Qf4 Kg8 27.Qxh6 Rc1+ 28.Rxc1 Rxc1+ 29.Qxc1] 23.Qg4+ Kxh7 24.Re3 Bxd2 25.Rh3+ Bh6 26.Qh5 Kg7 27.Rg3+ Kf8 0-1

Although I won this game the move 18...Bxc3? was extremely bad and it appears I panicked because I thought white had a winning kingside attack, when black actually has a lot of queenside pressure to counter it and it isn't as dangerous as it looks. It doesn't seem that moving the knight to h5 or g4, for instance, is losing, although white has the easier game.

Another lesson to come out of this game, as with many on the thread, is that it is one thing to correctly play the sac and another to correctly follow it up. Club players in my experience are much better at the first than at the second.

Basil
03-02-2009, 01:27 AM
Nice contribution to the thread. Good analysis. Excellent conclusion :wall:

Kevin Bonham
27-09-2009, 05:27 PM
Smerdon - Ly. Surfers Paradise open today. Last round must-win game for white as black lead the field by a point. Jono notes: "A new version of the ancient Bxh7 sac; Black must give up Q, for formally enough material but which is too unco-ordinated."

1.e4 c5 2.c3 Nf6 3.e5 Nd5 4.d4 cxd4 5.Nf3 e6 6.cxd4 b6 7.Nc3 Bb7 8.Bd3 Be7 9.O-O O-O 10.a3 Nxc3 11.bxc3 d6 12.Bf4 Nc6 13.exd6 Bxd6 14.Bxh7 Kxh7 15.Ng5 Kg6 16.Qd3 f5 17.Nxe6 Bxf4 18.Nxd8 Raxd8 19.Rfe1 Ne5 20.Qb5 Ng4 21.h3 Nf6 22.Re7 Bd5 23.Rxa7 Ne4 24.c4 Bg8 25.d5 Be5 26.Rd1 Rd6 27.Rd7 Rff6 28.Re7 Rfe6 29.Qe8 Kh6 30.Rxe6 Bxe6 31.Rf1 1-0

Kevin Bonham
28-09-2009, 04:33 AM
Another one from my archives.

r4rk1/pp1b2pp/2nqp3/3p4/3P2n1/2NB1N2/PP3PPP/2RQR1K1 w - - 0 19

... and the usual set of questions:

Black has just played 18...N(f6)-g4.

Q1. Should white play 19.Bxh7+? Why/why not?

Q2. If white plays Bxh7, should black take the bishop? Why/why not?

Q3. What did white play?

Q4. How did black respond?

Q5. The game ended on move 28. What was the result?

I think this one is very hairy to calculate because it isn't just the standard "do I have enough attack for the bishop?" conundrum. Here, both sides have a kingside attack.

Saragossa
28-09-2009, 05:57 PM
Q1) My instinct tells me that he shouldn't take away a valuable defender when it could just be a pawn grab. So no I don't believe Bxh7+ is good here because black's attack is too strong to take a piece away like this which could be valuable in stopping the exchange sacrifice on f3 (Be2).

Q2) No. After 19.Bxh7+ Kh8 20. Nc5 (this may be the intermediate move that gives white the edge. The reason is to defend the d4 pawn and possibly to make a defensive exchange sac on c6)20...Qb8 21. Bd3 (to defend the c5 knight after blacks c6 knight moves. And also getting out of the way of Rxf3 and then Qxh2+ forking the bishop and king winning two pieces for a rook) 21...Rxf3 22. Qxf3 Qxh2+ 23. Kf1 e5 24. Qh3+ Qxh3 25. gxh3 Nb4 26. Bf2 Nf6. This is a possible line where black is down the exchange with very complex play ensuing. I would like to think that white has an edge here although there are tricks.

Notably if white doesn't try to defend his d4 pawn black has a really cute pawn grab. 19. Bxh7+ Kh8 20.Bb1(Just as an example)20... Rxf3 21.Qxf3 [gxf3 runs into mate]21...Qxh2+ 22.Kf1 Qh1+ 23. Ke2 Nxd4+ and convenietly enough no matter where theking goes the knight either takes with check or defends his queen. So from that black lost 1 pawn,1 knight,1 rook and 1 queen where white lost 2 pawns, 1 knight, 1 rook and 1 queen. Made me laugh.

Thus I am opting for the somwhat clearer 21...a6 (camly kicking the knight, Now white has a few tries to mix things up that I have considered. One of them being: ) [22. Ne5 Ncxe5 23. dxe5 Bxc5 24. Bxc5 axc5 25. Qxg4 Rxa2] (with a good endgame resulting for black due to the passed d-pawn and initiative. Black's king safety shouldn't be a real issue.) After 21...a6 I am struggling to find anything concrete for white which leads me to believe 20. Nc5 is interesting but not best.

Since I cannot see anything better I assume I have missed something and all analysis above should be taken as possible line not 100% accurate.

Q3) I assume you were black due to the frenchy looking pawns on e6 and d5 and the bad atm but potentially dangerous bishop on d7. So after he took you calculated your way through and realised your attack was coming first (This answers Q4 aswell)

Q5) 0-1 white picked a bad line and fell straight into the deep-end.

All in all a very interesting position. I'll probably return to this thread a bit later on and see if I can work a bit more out on my line. note it was done without a board so the analysis could have huge oversights.

Capablanca-Fan
09-10-2009, 01:34 AM
An online non-lightning game with "Ariano": a sound Bxh7+ after a much better opening, but my opponent counter-sacrificed, leading only to a better endgame. But he collapsed quite quickly, losing loose pawns.

1.d4 d5 2.c4 Nf6?! 3.cxd5 Nxd5 4.Nf3 e6 5.e4 Nb6 6.Nc3 Bb4 7.Bd3 0-0 8.0-0 c5 9.e5 Nc6?! 10.Bxh7+! Kxh7 11.Ng5+ Kg6 12.h4 There were better moves, e.g. [12.Qg4 f5 13.Qg3 Qe8 14.Nb5;
12.Ne2 Nxe5 13.Qc2+ Kf6 14.dxe5+ Ke7 15.a3] 12...Nxe5 13.h5+ Kf6 14.dxe5+ Ke7 15.Nh7 Qxd1 16.Rxd1 Rh8 17.Bg5+ f6 18.Nxf6 Kf7 19.Nfe4 Rxh5 20.g4 Rh7 21.Nd6+ Kg8 22.Nce4 Nd5 23.a3 Ba5 24.Nxc5 g6 25.Nxc8 Rxc8 26.Nxe6 Nc7 27.Rac1 Re8 28.Nxc7 Bxc7 29.f4 Bb6+ 30.Kg2 Rf8 31.Rd6 Be3 32.Rxg6+ Kf7 33.Rf6+ Kg8 34.Rxf8+ Kxf8 35.Rc8+ Kg7 36.Bf6+ Kg6 37.f5+ Kh6 38.Rc3 Bd4 39.Rh3#

Kevin Bonham
09-10-2009, 03:06 AM
Answers to #193:

r4rk1/pp1b2pp/2nqp3/3p4/3P2n1/2NB1N2/PP3PPP/2RQR1K1 w - - 0 19

Black has just played 18...N(f6)-g4.

Q1. Should white play 19.Bxh7+? Why/why not?

Very hard to say. The tactics are so messy because of the counter-sac. Basically black can't take the bishop (see below) so white gets a pawn and the onus is on black to make use of the tempo gained when the bishop retreats.

After 20.Nb5! Qb8 as suggested by Saragossa it's not quite clear whether 21.Bc2 or 21.Bd3 is best. (21.Bb1 is another option). In all cases black sacs on f3 and takes on h2. The different moves from there lead to quite different apparent best lines; white might return material for a better position, or end up exchange up for a pawn, etc. All in all it seems white has a solid plus but it's a mess even with computer assistance, and 19.Nb5 instead of taking on h7 can't be much worse.

Q2. If white plays Bxh7, should black take the bishop? Why/why not?

Definitely not since the simple Ng5+ then Qxg4 puts white a pawn up and black has no compensation; furthermore, white may have a dangerous attack.

Q3. What did white play?

White wimped out with 19.h3?

Q4. How did black respond?

19...Rxf3! Thematic. Since 20.Qxf3?? Qh2+ 21.Kf1 Nxd4! sets up a really cute mating net, White was only able to stay in the game with 20.hxg4!

Q5. The game ended on move 28. What was the result?

White suffered tactical meltdown after giving black the initiative.

Full game with some of the possible lines shown:

Bemrose (2090) - Bonham (1879) HICC Champs 2000.

1.e4 e6 2.d4 d5 3.Nd2 Nf6 4.e5 Nfd7 5.Bd3 c5 6.c3 Nc6 7.Ne2 Qb6 8.Nf3 f6 9.exf6 Nxf6 10.0-0 Bd6 11.Bf4 Qc7 12.Bxd6 Qxd6 13.Re1 0-0 14.Ng3 cxd4 15.cxd4 Qf4 16.Rc1 Bd7 17.Ne2 Qd6 18.Nc3 Ng4 19.h3 [19.Bxh7+ Kh8 (19...Kxh7? sample line 20.Ng5+ Kg8 21.Qxg4 Qf4 and now white can swap queens but probably stronger is 22.Qh5! Qxf2+ 23.Kh1 Qf5 24.g4! Be8 25.Qh4 Qg6 26.Nxe6 and white needs to be very careful but has a big material lead.) 20.Nb5 Qb8 21.Bc2 (21.Bd3 Rxf3 22.Qxf3 Qxh2+ 23.Kf1 Nb4 24.Nc7 Nxd3 25.Qxd3 Rf8 26.Qh3+ Qxh3 27.gxh3 Nxf2) 21...Rxf3 22.Qxf3 Qxh2+ 23.Kf1 Nce5 24.Qh3+ Qxh3 25.gxh3 Nf3 26.Nd6 Nxe1 27.Rxe1 Nf6 28.Bg6] 19...Rxf3 20.hxg4 Rf7 21.Ne2 Raf8 22.f3 e5 23.dxe5 Nxe5 24.b3?? [24.Nd4 holds] 24...Rxf3 [24...Qb6+ 25.Kh1 Qh6+ 26.Kg1 Qe3+ 27.Kh1 Nxd3 is cute] 25.Be4 Qb6+ [Best here is actually 25...Rd3 since if 26.Bxd3 Nxg4 is crushing] 26.Qd4 dxe4 27.Rc5 Nd3 28.gxf3 Qxc5 White resigned 0-1

One of my more speccy wins since I sac the same rook on f3 twice and he can't take it either time, correctly doesn't take it either time and still loses. However my opening play is pretty dodgy; 19.Bxh7 isn't the only point at which white could have gone +/-.

(If it looks familiar to a reader, I posted it before several years back on the French theory thread.)

Capablanca-Fan
09-10-2009, 11:37 AM
Bemrose (2090) - Bonham (1879) HICC Champs 2000.

1.e4 e6 2.d4 d5 3.Nd2 Nf6 4.e5 Nfd7 5.Bd3 c5 6.c3 Nc6 7.Ne2 Qb6 8.Nf3 f6 9.exf6 Nxf6 10.0-0 Bd6 11.Bf4 Qc7 12.Bxd6 Qxd6 13.Re1 0-0 14.Ng3 cxd4 15.cxd4 Qf4 16.Rc1 Bd7 17.Ne2 Qd6 18.Nc3 Ng4 19.h3 [19.Bxh7+ Kh8 (19...Kxh7? sample line 20.Ng5+ Kg8 21.Qxg4 Qf4 and now white can swap queens but probably stronger is 22.Qh5! Qxf2+ 23.Kh1 Qf5 24.g4! Be8 25.Qh4 Qg6 26.Nxe6 and white needs to be very careful but has a big material lead.) 20.Nb5 Qb8 21.Bc2 (21.Bd3 Rxf3 22.Qxf3 Qxh2+ 23.Kf1 Nb4 24.Nc7 Nxd3 25.Qxd3 Rf8 26.Qh3+ Qxh3 27.gxh3 Nxf2) 21...Rxf3 22.Qxf3 Qxh2+ 23.Kf1 Nce5 24.Qh3+ Qxh3 25.gxh3 Nf3 26.Nd6 Nxe1 27.Rxe1 Nf6 28.Bg6] 19...Rxf3 20.hxg4 Rf7 21.Ne2 Raf8 22.f3 e5 23.dxe5 Nxe5 24.b3?? [24.Nd4 holds] 24...Rxf3 [24...Qb6+ 25.Kh1 Qh6+ 26.Kg1 Qe3+ 27.Kh1 Nxd3 is cute] 25.Be4 [25.gxf3 Nxf3+ 26.Kf2 Qh2+ 27.Ke3 Qh6+ 28.Kf2 Ne5+ 29.Kg2 Rf2+! 30.Kxf2 Nxg4+ 31.Kg2 Qh2+ 32.Kf3 Qf2# is one line, for the recordóJono] 25... Qb6+ [Best here is actually 25...Rd3 since if 26.Bxd3 Nxg4 is crushing] 26.Qd4 dxe4 27.Rc5 Nd3 28.gxf3 Qxc5 White resigned 0-1
[/QUOTE]

Igor_Goldenberg
15-10-2009, 12:57 PM
I missed the beginning of the debate and don't have an engine running at the moment, but what about:
19.Bxh7 Kh8 20.Ne5 After 20...Nxe5 21.de5 Nxe5 22.Qh5 white seems much better.

Kevin Bonham
15-10-2009, 02:46 PM
I missed the beginning of the debate and don't have an engine running at the moment, but what about:
19.Bxh7 Kh8 20.Ne5 After 20...Nxe5 21.de5 Nxe5 22.Qh5 white seems much better.

Yes 20.Ne5 seems about as strong as 20.Nb5. An option for black is to play 20...Ncxe5 then after 21.dxe5 black need not play ...Nxe5 (when 22.Bb1 first then Qh5 must win) but might instead play ...Qb6 (...Qb4 is also an option but then 22.Be4!). 21...Qb6 forces 22.Qxg4 Rxf2 23.Kh1 Kxh7 and now 24.Nxd5 winning a pawn seems best - looks like white probably wins the heavy piece ending despite black's strongly placed rook on f7.

Zuker
26-10-2009, 03:22 PM
Hi All,
I'm not sure how useful this is for many of the members, but I recently published a book (more like a training kit) on the Greek Gift.
I don't think it is available yet in Oz, but there is some hope it will be soon.

Four exercise samples are available on the book's website (http://www.bishop-sacrifice.com/).

Kevin Bonham
02-02-2010, 12:48 AM
Book above was reviewed at ChessCafe recently http://www.chesscafe.com/Reviews/books.htm though the review is not particularly analytical or in-depth.

One of the author's other books made the popular-voting shortlist for Chesscafe Book of the Year.

CameronD
05-02-2010, 09:29 AM
Hi

Had an internet game recently where i played a sac.

Not sure if its correct, what do you people think

[WhiteElo "1680"]
[BlackElo "1675"]
[Opening "Caro-Kann defense"]
[ECO "B12"]
[TimeControl "900+0"]}

1. d4 {0:14:53} c6 {0:14:58} 2. e4 {0:14:47} d6 {
0:14:57} 3. Nc3 {0:14:35} Qc7 {0:14:53} 4. Bf4 {0:14:30} Nf6 {0:14:45} 5. Bc4 {
0:14:22} e6 {0:14:41} 6. Nf3 {0:14:12} Nbd7 {0:14:39} 7. Qe2 {0:14:06} a6 {
0:14:33} 8. Ng5 {0:13:47} h6 {0:14:24}

Is 9. Nxe6 sound or playable??

Basil
05-02-2010, 10:49 AM
Certainly looks tempting with e5 to follow.

Kevin Bonham
05-02-2010, 01:16 PM
I don't think the sac is losing but I do think it's unnecessary. White will probably get about sufficient play for it but that's actually nothing to write home about since white had a good position anyway and there is no need to give black anything. There is no real force in the sac - if white succeeds in kicking the Nf6 by means of e5 thus allowing Qh5 the problem is that the queen is basically a lone attacker. If the bishop has recaptured on e6 black gets rid of it by ...Nb6 and if not black plays ...Nd5 after e5 and the queen has no support. There is long-term positional compensation though (in the line 9.Nxe6 fxe6 10.Bxe6 Nb6 11.Bxc8 with e5), black will be defending a cramped position, possibly with his king on a dodgy square, all through the middlegame.

On move 8 white has a huge advantage in development and a considerable advantage in space. There's no need to play Ng5-xe6 in this sort of position. I'd just castle and probably build up an early kingside attack, possibly with e5 at a suitable moment. If black is good enough to neutralise the position then good luck to him, at least he won't be winning (which he will if the sac runs out of puff.)

By the way although a computer opening book might call this a Caro-Kann, 1...c6 with 2...d6 is actually more like a Pribyl, which is normally seen via the move order 1.e4 d6 2.d4 Nf6 3.Nc3 c6 (though the move order from your game with 1...c6 and 2...d6 was seen in one of Kasparov's games against Deep Blue). The correct name for 3...Qc7 is most probably "rubbish".

Capablanca-Fan
05-02-2010, 06:56 PM
I would add, although many beginners' books show Bc4 and Bf4 as an ideal position for White, in reality they are open to tempo-gaining P pushes. In many Pirc-type positions, which this resembles, Black likes to play ... e5 and ... b5, and here he can gain time as well by the "biff" (C.J.S. Purdy's term).

Kevin Bonham
28-01-2012, 09:29 PM
Another book about Bxh7:

http://shop.chesscafe.com/Sacking_the_Citadel.asp

Also an article about Bxh6:

http://www.chesscafe.com/skittles/skittles.htm

Kevin Bonham
29-10-2012, 04:20 PM
This one I think is at the easy end of the scale.

r2q1rk1/pbpn1ppp/1pnpp3/4P3/3P1P2/2PB1N2/P1P1Q1PP/R1B2RK1 w - - 0 11

White to move

1. To take or not to take?

2. How long would you think about it for?

3. If you take should black take it?

James Peirce
13-05-2013, 02:52 PM
1. Take it
2. 2 seconds
3. No because Ng5+ check followed by queen invasion will win

Oepty
13-05-2013, 07:01 PM
1. Take it
2. 2 seconds
3. No because Ng5+ check followed by queen invasion will win

It does appear that 1. Bxh7 Kxh7 2. Ng5+ wins.

James Watson
15-05-2013, 02:13 AM
r3k2r/p1qbnppp/1pn1p3/2ppP3/P2P4/2PB1N2/2P2PPP/R1BQ1RK1 b kq - 0 1

I had decided to try out the French for the first time but felt I had played sub optimally to reach this position. White had just played 0-0 and blacks most natural response would be to follow suit, but would this be wise since Bxh7 might be in the air?

Capablanca-Fan
15-05-2013, 05:57 AM
1. Bxh7+ Kxh7 2. Ng5+ Kg6 [2... Kg8 3. Qh5 Rfe8 4. Qh7+ Kf8 5. Qh8+ Ng8 6. Nh7+ Ke7 7. Bg5+] 3. Qg4 f5 4. Qg3 {threatening a discovered check with the N}

I had decided to try out the French for the first time but felt I had played sub optimally to reach this position. White had just played 0-0 and blacks most natural response would be to follow suit, but would this be wise since Bxh7 might be in the air?
Indeed, it looks like Black played too straightforwardly and allowed White a good position where his doubled Ps are in little danger. It's not lost yet. However, it would be after 1... 0-0 2. Bxh7+ as shown in the note. An experienced player would not calculate that much, but know that it would work because Black can't play ... Nf6 or ... Bf5 guarding the h7 mate square later. The dark squared B is important to stop 3... Kh6, which can often be the best move if it's not there. In general, a e5 v. e6 P centre can scream for this sace.

Kevin Bonham
15-05-2013, 10:13 AM
This is interesting because after the obvious 1...0-0 2.Bxh7+ Kxh7 3.Ng5+ Kg6 it's not that clear that Qg4 is crushing after ...f6 (5.Nxe6+ is a self-pin) while Qd3+ doesn't seem to work after ...Nf5 and ...f6. The correct move appears to instead be 4.h4! which I believe wins.

Capablanca-Fan
15-05-2013, 11:13 AM
This is interesting because after the obvious 1...0-0 2.Bxh7+ Kxh7 3.Ng5+ Kg6 it's not that clear that Qg4 is crushing after ...f6 (5.Nxe6+ is a self-pin) while Qd3+ doesn't seem to work after ...Nf5 and ...f6. The correct move appears to instead be 4.h4! which I believe wins.
I didn't consider the self-pin. My first thought was 4.h4 but wasn't sure how to continue after 4... Rh8.

Kevin Bonham
15-05-2013, 11:27 AM
I didn't consider the self-pin. My first thought was 4.h4 but wasn't sure how to continue after 4... Rh8.

Now 5.Qg4 because after ...f6 6.Nxe6+ Kf7 7.Qxg7+ mates. ...Rh8 unprotects f6; in the line with 4.Qg4 f6 5.Nxe6+ Kf7 6.Qxg7+ black can just take the knight. Possibly white is then still winning but it's messy and white has invested two pieces.

As a lifelong French player I have a fairly advanced paranoia of getting Bxh7+ed in positions like this. Strangely this doesn't seem to extend to a more useful paranoia of getting Qxh7#ed. :rolleyes:

Capablanca-Fan
16-05-2013, 04:33 AM
Now 5.Qg4 because after ...f6 6.Nxe6+ Kf7 7.Qxg7+ mates. ...Rh8 unprotects f6; in the line with 4.Qg4 f6 5.Nxe6+ Kf7 6.Qxg7+ black can just take the knight. Possibly white is then still winning but it's messy and white has invested two pieces.
Right! John Nunn mentioned this sort of thing in his Secrets of Practical Chess. Kotov's famous Think Like a Grandmaster advocated selecting candidate moves and analysing from them, and not going back to old candidates. But Nunn gave an example of where analysis from one candidate move actually provided a clue of how to salvage a previously rejected candidate. I need to put this into practice more often.

Kevin Bonham
19-04-2015, 05:59 PM
Variation on a theme:

Stockfish - Bonham, blitz

1.Nf3 e6 2.d4 a6 3.e4 d5 4.Nbd2 Nf6 5.e5 Nfd7 6.Bd3 c5 7.c3 Nc6 8.0-0 cxd4 9.cxd4 f6 10.exf6 Nxf6 11.Ng5 Bd6 12.Ndf3 0-0

Here white played 13.Nxh7 setting up a kind of Greek Gift by proxy after 13...Nxh7 14.Bxh7+

OK, it's a no-brainer that we take the thing 14...Kxh7 otherwise we are a pawn down with a smashed position. And of course it will be 15.Ng5+

But then ... g6 or g8 for the king? Prospects? Do we argue with Stockfish or is its idea correct?

Jesper Norgaard
20-04-2015, 12:01 AM
Variation on a theme:

Stockfish - Bonham, blitz

1.Nf3 e6 2.d4 a6 3.e4 d5 4.Nbd2 Nf6 5.e5 Nfd7 6.Bd3 c5 7.c3 Nc6 8.0-0 cxd4 9.cxd4 f6 10.exf6 Nxf6 11.Ng5 Bd6 12.Ndf3 0-0

Here white played 13.Nxh7 setting up a kind of Greek Gift by proxy after 13...Nxh7 14.Bxh7+

OK, it's a no-brainer that we take the thing 14...Kxh7 otherwise we are a pawn down with a smashed position. And of course it will be 15.Ng5+

But then ... g6 or g8 for the king? Prospects? Do we argue with Stockfish or is its idea correct?

There is an old joke. If Tal sacrifices a piece you should accept it and see what happens. If Petrosian sacrifices a piece, you should resign. I think this is of the latter category, without having any hard evidence.

Isn't Kg8 just mated? Isn't Kg6 just losing a rook (in effect therefore the exchange) after 15...Kg6 16.Qd3+ Rf5 17.g4?

Kevin Bonham
20-04-2015, 11:26 AM
There is an old joke. If Tal sacrifices a piece you should accept it and see what happens. If Petrosian sacrifices a piece, you should resign. I think this is of the latter category, without having any hard evidence.

Isn't Kg8 just mated? Isn't Kg6 just losing a rook (in effect therefore the exchange) after 15...Kg6 16.Qd3+ Rf5 17.g4?

The answers seem to be not obviously, and no because Black plays not 16...Rf5 but 16...Kf6 since the knight check on h7 is harmless (black is happy to give back the exchange.)

Here are some possible lines:

1.Nf3 e6 2.d4 a6 3.e4 d5 4.Nbd2 Nf6 5.e5 Nfd7 6.Bd3 c5 7.c3 Nc6 8.0-0 cxd4 9.cxd4 f6 10.exf6 Nxf6 11.Ng5 Bd6 12.Ndf3 0-0 13.Nxh7 Nxh7 14.Bxh7+ Kxh7 15.Ng5+ Kg8 [15...Kg6 16.Qd3+ (16.Qg4 Qd7 17.f4 Kf6) 16...Kf6 17.Re1 (17.Nh7+ Kf7 18.Nxf8 is harmless) ] 16.Qh5 Rf5 17.f4 [17.Qh7+ Kf8 18.Qh8+ Ke7 19.Qxg7+ Ke8 20.Re1 Qf6 is not enough for white]

Ian Rout
20-04-2015, 02:42 PM
I think that you're allowed to argue with Stockfish, because Stockfish doesn't agree with Stockfish. Both Stockfish 6 and 5 as well as Houdini 4 on my laptop (albeit nearly three years old) in analysis mode prefer 13.Rel and rate 13.Nxh7 about even. Leaving Stockfish 6 running for half an hour it claims a slight edge for Black with 15...Kg6 and Black delivering perpetual check after Kg8. Maybe the choice of 13.Nxh7 relates to the settings or the time limit.

Kevin Bonham
20-04-2015, 03:17 PM
I think that you're allowed to argue with Stockfish, because Stockfish doesn't agree with Stockfish. Both Stockfish 6 and 5 as well as Houdini 4 on my laptop (albeit nearly three years old) in analysis mode prefer 13.Rel and rate 13.Nxh7 about even. Leaving Stockfish 6 running for half an hour it claims a slight edge for Black with 15...Kg6 and Black delivering perpetual check after Kg8. Maybe the choice of 13.Nxh7 relates to the settings or the time limit.

Yes. I still have Stockfish 4.2 and the time limit is 4+2. Playing the same line again it will sometimes play 13.Nxh7 and sometimes play 13.Re1, which I was fully expecting (and after more analysis it thinks 13.Re1 is better). It also sometimes plays a different piece sacrifice, 10.Ng5, which seems to be not too flash either.

MichaelBaron
21-04-2015, 10:52 AM
Even though black's position appears to be defendable, playing for black with a King on f8 will be highly unpleasant so black too needs a computer to help him defend :)

James Peirce
26-08-2015, 11:08 AM
In this game there was both a Bxh7 and Bxh2 sacrifice with a Bxg2 thrown in for good measure as well, computer analysis indicates that Bxh7 didn't work but it was difficult to calucate in blitz time control(5mins+5secs)
[Site "chess.com"]
[Date "2015.08.26"]
[White "admiral-adama(online opponent)"]
[Black "James W Peirce"]
[Result "0-1"]
[WhiteElo "1727"]
[BlackElo "1696"]
[ECO "C10"]
[Opening "French: Rubinstein, 4...Nf6"]

1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nf6 5.Ng3 Bd6 6.Nf3 b6 7.Bd3 Bb7 8.Be3 Nbd7
9.c3 c5 10.O-O O-O 11.Re1 Nd5?! {this move starts bewildering complications
that last for more than 15 moves.} 12.Bxh7+ Kxh7 13.Ng5+ Kg8 14.Qc2 N7f6
15.Nh5 g6 16.Nxe6 Nxe3 17.Rxe3 Bxh2+ 18.Kh1 Bxg2+ 19.Kxg2 Qd5+ 20.Rf3 Nxh5
21.Nc7 Qg5+ 22.Kxh2 Nf4 23.Rg3 Qh4+ 24.Kg1 Rac8 25.Nd5? Nxd5 26.Rxg6+ fxg6
27.Qxg6+ Kh8 {#R} 0-1

Kevin Bonham
26-08-2015, 06:20 PM
Interesting game. It's a fairly clear case where the sac is not on because knights cover h7, but ...g6 gave white some of what he wanted, just not enough.

James Peirce
03-11-2015, 03:25 PM
This is perhaps one of the most complex Bxh7 sacrifices
James Peirce vs Patrick Grace
Fritz suggests that declining was the best course of action, after Kxh7 the amount of sub-variations in the moves after is enormous.
1.e4 e5 2.f4 Bc5 3.Nf3 exf4 4.d4 Bb6 5.Bxf4 d5 6.e5 Ne7 7.Bd3 Nf5 8.c3 O-O
9.g4 Nh4 10.Bxh7+ Kxh7 11.Qd3+ Kg8 12.Ng5 Ng6 13.Qh3 Re8 14.Qh7+ Kf8 15.h4
Nxf4 16.Qh8+ Ke7 17.Qxg7 Nd3+ 18.Kd2 Nxe5 19.dxe5 Be6 20.Nxe6 Kxe6 21.Rf1 Qe7
22.Rf6+ Kd7 23.Rxf7 Nc6 24.Rxe7+ Rxe7 25.e6+ Kxe6 26.Qg6+ Kd7 27.Qf5+ Re6
28.Na3 Re8 29.Re1 Nd8 30.Nb5 c6 31.Nd4 Bxd4 32.cxd4 Kc7 33.Rxe6 Rxe6 34.g5 Re4
35.Qh7+ Kb6 36.g6 Rxd4+ 37.Ke3 Rg4 38.g7 {#r} 1-0

Kevin Bonham
03-11-2015, 07:49 PM
The important principle here is that in a lot of cases if black declines he is just a pawn down. But in this case declining is a serious option - firstly because he will recover the pawn anyway, and secondly because white's kingside is very loose.

Capablanca-Fan
04-11-2015, 03:03 AM
James Peirce vs Patrick Grace
C-F comments:
1.e4 e5 2.f4 Bc5 3.Nf3 exf4 {Terrible. Take the P on move 2 if you want, and make White work to get it back. Or follow 2... Bc5 with 3... d6. C.J.S. Purdy would have recoiled at the game move exposing the B to ‘biff’, allowing the opponent to make desirable moves while attacking it.} 4.d4 Bb6 5.Bxf4 d5 6.e5 [6.exd5 {to take advantage of the lead in development thanks to Black's tempo loss. Black has not enough development to justify delaying recapturing with ... Qxd5. This leaves the Q is misplaced there, and white will soon castle and and use the f-file. White still has a strong position after the game move though}] 6... Ne7 7.Bd3 [7.Be2 {Black should be planning ... c5, so White should keep the Q's protection on d4 and consolidate.}] 7... Nf5 [7...Bf5 {to exchange White's strong B, and relieve a cramped position by exchanges.}] 8.c3 O-O 9.g4 [9.Qc2 {shouldd be given serious consideration. Black would have nothing better than the seriously weakening 9... g6, so White can then attack with little risk. The game move is loosening as KB says.}] 9... Nh4 10.Bxh7+ Kxh7 11.Qd3+ Kg8 12.Ng5 Ng6 13.Qh3 Re8 14.Qh7+ Kf8 15.h4
Nxf4 16.Qh8+ Ke7 17.Qxg7 Nd3+ 18.Kd2 Nxe5 19.dxe5 Be6 20.Nxe6 Kxe6 21.Rf1 Qe7
22.Rf6+ Kd7 23.Rxf7 Nc6 24.Rxe7+ Rxe7 25.e6+ Kxe6 26.Qg6+ Kd7 27.Qf5+ Re6
28.Na3 Re8 29.Re1 Nd8 30.Nb5 c6 31.Nd4 Bxd4 32.cxd4 Kc7 33.Rxe6 Rxe6 34.g5 Re4
35.Qh7+ Kb6 36.g6 Rxd4+ 37.Ke3 Rg4 38.g7 {#r} 1-0

Kevin Bonham
01-03-2017, 11:16 PM
Your name is Anna Muzychuk and you are one down with two games left against your upstart Chinese opponent who has just played 13...b5. Do you feel lucky? Apart from feeling lucky to be Anna Muzychuk, that is?

1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5 Nfd7 5.f4 c5 6.Nf3 Nc6 7.Be3 Be7 8.Qd2 0-0 9.dxc5 Bxc5 10.0-0-0 Qa5 11.a3 Be7 12.Bd3 a6 13.h4 b5

Basil
05-03-2017, 11:16 PM
I'm plonking for yep. Do tell.

Kevin Bonham
06-03-2017, 12:31 AM
White played the sacrifice and black was smashed. (Actually 21.Qxe6+ would have ended the game several moves earlier.) The smashing method involving a second piece sac in the centre is unusual.

1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5 Nfd7 5.f4 c5 6.Nf3 Nc6 7.Be3 Be7 8.Qd2 0-0 9.dxc5 Bxc5 10.0-0-0 Qa5 11.a3 Be7 12.Bd3 a6 13.h4 b5 14.Bxh7+ Kxh7 15.Qd3+ Kg8 16.Ng5 f5 17.Nxd5 b4 18.Nxe7+ Nxe7 19.Bd2 Rb8 20.Qd6 Qc5 21.Bxb4 Qxd6 22.Bxd6 Ng6 23.Nxe6 Re8 24.Bxb8 Rxe6 25.g3 Bb7 26.Rh2 Nc5 27.Rd8+ Kh7 28.Bd6 Ne4 29.h5 Nh8 30.h6 Nf7 31.Rd7 Rxd6 32.Rxf7 1-0

13...b5?? enabled the sac by both unprotecting the knight on c6 and blocking the queen's defence of d5, thereby allowing 17.Nxd5 to work (if black takes back, white will take on d5 and c6 then swing to g6 and all over). Other 13th moves by black would have avoided this.

Agent Smith
06-03-2017, 10:48 AM
Rogers wrote up this game, though not quite Bxh7

[Event "Sharjah Grand Prix 2017"]
[Site "Sharjah UAE"]
[Date "2017.02.24"]
[Round "6.6"]
[White "Nepomniachtchi, Ian"]
[Black "Li, Chao b"]
[Result "1-0"]
[WhiteElo "2749"]
[BlackElo "2720"]
[ECO "C42"]
[EventDate "2017.02.18"]
[WhiteTitle "GM"]
[BlackTitle "GM"]
[Opening "Petrov"]
[Variation "classical attack, Marshall variation"]
[WhiteFideId "4168119"]
[BlackFideId "8604436"]
[Annotator "Rogers"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6 7. O-O O-O 8. c4 c6 9. Nc3 Nxc3 10. bxc3 dxc4 11. Bxc4 Bf5 12. Bg5 Qc7 13. Re1 h6 14. Nh4 Bh7 15. Bxh6 {Nepo's home preparation. The point is that
} 15. ... Bxh2+
( 15. ... gxh6 16. Qg4+ Kh8 17. Nf5 Bxf5
( 17. ... Rg8 18. Re8 )
18. Qxf5 f6 19. Re6 )
16. Kh1 Bf4 17. Bxg7 Kxg7 18. Qg4+ Kh8 19. Nf5 Bxf5 20. Qxf5 Qd6 21. g3 Bh6 22. Kg2 b5 23. Bb3 Qg6 24. Qxg6 fxg6 25. Re7 g5 26. Re6 Kg7 27. Rh1 Rh8 28. Re7+ Kg6
( 28. ... Kf6 29. Rhe1 g4 30. R1e6+ Kg5 31. Bc2 Rg8 32. Rf7 Kh5 33. f4 Bxf4 34. gxf4 Rg7 35. Rf5+ Rg5 36. Rxg5+ Kh4 37. Rh6# )
29. Bc2+
( 29. Bc2+ Kf6 30. Rhe1 g4 31. R1e6+ Kg5 32. Rg6+ Kh5 33. Re5+ Bg5 34. Rexg5# )
1-0

Bulldozer
06-03-2017, 02:32 PM
13...b5?? enabled the sac by both unprotecting the knight on c6 and blocking the queen's defence of d5, thereby allowing 17.Nxd5 to work (if black takes back, white will take on d5 and c6 then swing to g6 and all over). Other 13th moves by black would have avoided this.
13... b5 might make it easier for Anna to find a win but other moves on the Queen side would be blunders too. The weakness of the c6 knight was not very important as 17. Nxd5 was not the only move to continue the attack (17. Qe2 seems even stronger). I think Tan didn't have to keep the knight protected - she should have prevented the Bxh7 shot in the first place. Bxh7 became possible only after 13. h4, so that the *h* pawn was ready to recapture the bishop on g5 opening the h file. Tan didn't pay attention to that strong pawn move.

Desmond
27-06-2020, 12:54 PM
Position I had in a rapid game. What do you think, should white go for the bishop sac? What's the evaluation, does it win? Does white have better? Will post the answer and game continuation (which may or may not be the same :doh:) after people have a chance to work it out.

r1bq1rk1/pp2nppp/4p3/n7/3P4/2NB1N2/PP3PPP/R2QR1K1 w - - 0 14

Patrick Byrom
27-06-2020, 11:22 PM
Position I had in a rapid game. What do you think, should white go for the bishop sac? What's the evaluation, does it win? Does white have better? Will post the answer and game continuation (which may or may not be the same :doh:) after people have a chance to work it out.
I think the sac is sound. Assuming Black accepts, and White then checks with Ng5: Kg8 seems fatal after Qh5, while Kh6 or Kg6 allows Qg4 (possibly followed by Nce4). I can't find anything better.

According to Vukovic, the sac should work:
4242

Desmond
05-07-2020, 09:12 AM
Position I had in a rapid game. What do you think, should white go for the bishop sac? What's the evaluation, does it win? Does white have better? Will post the answer and game continuation (which may or may not be the same :doh:) after people have a chance to work it out.

r1bq1rk1/pp2nppp/4p3/n7/3P4/2NB1N2/PP3PPP/R2QR1K1 w - - 0 14


I think the sac is sound. Assuming Black accepts, and White then checks with Ng5: Kg8 seems fatal after Qh5, while Kh6 or Kg6 allows Qg4 (possibly followed by Nce4). I can't find anything better.

According to Vukovic, the sac should work:
4242

Yes Patrick pretty much has it. The computer recommends the sac +3 and for black to decline the sac with ...Kh8. Second choice is to accept and go ...Kg6 Qg4, though I played h4 instead. I missed a few of the best lines but had a strong attack and won in the end.

I was surprised to see that the computer also recommended b4 instead of the immediate bishop sac, as almost as strong a line. To be honest this move would never occur to me as the loose knight on a5 is nice to have when you're bringing the queen to h5.


1. d4 Nf6 2. c4 e6 3. Nf3 c5?! {d5} 4. e3?! {d5} 4... cxd4 5. exd4 d5 6. Nc3 Bb4 { B14 Nimzo-Indian Defense: Panov Attack, Main Line } 7. Bd3 O-O 8. O-O Nc6 9. Bg5 dxc4 10. Bxc4 Be7 11. Re1 Na5 12. Bd3 Nd5?? { (0.45 → 3.90) Blunder. b6 was best. } (12... b6) 13. Bxe7 Nxe7 14. Bxh7+ Kxh7?! { (4.01 → 5.74) Inaccuracy. Kh8 was best. } (14... Kh8) 15. Ng5+ Kg6 16. h4?? { (4.98 → 0.48) Blunder. Qg4 was best. } (16. Qg4 f5 17.Qg3 Kf6 18.Rxe6+ Bxe6 19.Qe5+ Kg6 (19...Kxg5 20.Qxg7+ Kh5 21.g4+ fxg4 22.Ne4 Nf5 23.Qh7+ Nh6 24.Ng3+ Kg5 25.Qg7+ Kf4 26.Qe5+ Kf3 27.Qe3#) 20.Nxe6 Rf7 21.Nxd8 Rxd8 22.Qe6+ Rf6 23.Qxe7) 16... Nf5?? { (0.48 → 3.07) Blunder. f5 was best. } (16... f5 17. Qd3) 17. Qg4 Nh6?? { (3.02 → 18.38) Blunder. Kh6 was best. } (17... Kh6 18. Qf4) 18. h5+ Kf6 19. Nh7+ Ke7 20. Qxg7 Nf5 21. Qf6+ Kd7 22. Nxf8+ Qxf8 23. d5 Qe7 24. dxe6+ fxe6 25. Rad1+ Ke8 26. Qg6+ Kf8 27. Nd5?! { (8.95 → 5.75) Inaccuracy. g4 was best. } (27. g4 Bd7) 27... Qf7 28. Qxf7+?! { (5.81 → 4.44) Inaccuracy. Nc7 was best. } (28. Nc7 Qxg6 29. hxg6 Rb8 30. Rd8+ Ke7 31. Rd5 Nh4 32. Rg5 Bd7 33. Nd5+ Kd6 34. Nf6 Ke7) 28... Kxf7 29. Nc7 Rb8 30. g4 Nh6?! { (4.29 → 6.18) Inaccuracy. Nh4 was best. } (30... Nh4 31. Rd3) 31. g5 Nf5 32. Rd8?! { (4.68 → 3.44) Inaccuracy. g6+ was best. } (32. g6+ Kf6 33. Rd8 Nc6 34. Rf8+ Kg5 35. g7 Nxg7 36. Rg8 e5 37. Rxg7+ Kh6 38. Rg6+ Kh7) 32... Nc6 33. Rh8 Kg7 34. Re8 Nd6?? { (2.92 → 6.87) Blunder. Nfd4 was best. } (34... Nfd4 35. Kg2) 35. Nxe6+ Bxe6 36. R8xe6 Rd8 37. Rg6+ Kh7 38. Ree6 Nf5 39. Rgf6?! { (5.78 → 4.01) Inaccuracy. Ref6 was best. } (39. Ref6) 39... Nfd4? { (4.01 → 8.84) Mistake. Ncd4 was best. } (39... Ncd4 40. Rf7+ Kg8 41. Ref6 Nf3+ 42. Kf1 Nxg5 43. Rxb7 Nh4 44. Rxa7 Nhf3 45. Rb6 Re8 46. Kg2) 40. Rh6+ Kg7 41. Reg6+ Kf7 42. Rh7+ Kf8 43. Rgg7 Ne5 44. h6 Nf5? { (9.06 → Mate in 1) Checkmate is now unavoidable. Ndf3+ was best. } (44... Ndf3+ 45. Kg2 Nh4+ 46. Kf1 Neg6 47. Rxb7 Kg8 48. Rbg7+ Kf8 49. Rxa7 Kg8 50. Rhf7 Nf8 51. f4) 45. Rh8# { White wins by checkmate. } 1-0

Patrick Byrom
05-07-2020, 01:55 PM
Yes Patrick pretty much has it. The computer recommends the sac +3 and for black to decline the sac with ...Kh8. Second choice is to accept and go ...Kg6 Qg4, though I played h4 instead. I missed a few of the best lines but had a strong attack and won in the end. I was surprised to see that the computer also recommended b4 instead of the immediate bishop sac, as almost as strong a line. To be honest this move would never occur to me as the loose knight on a5 is nice to have when you're bringing the queen to h5.


1. d4 Nf6 2. c4 e6 3. Nf3 c5?! {d5} 4. e3?! {d5} 4... cxd4 5. exd4 d5 6. Nc3 Bb4 { B14 Nimzo-Indian Defense: Panov Attack, Main Line } 7. Bd3 O-O 8. O-O Nc6 9. Bg5 dxc4 10. Bxc4 Be7 11. Re1 Na5 12. Bd3 Nd5?? { (0.45 → 3.90) Blunder. b6 was best. } (12... b6) 13. Bxe7 Nxe7 14. Bxh7+ Kxh7?! { (4.01 → 5.74) Inaccuracy. Kh8 was best. } (14... Kh8) 15. Ng5+ Kg6 16. h4?? { (4.98 → 0.48) Blunder. Qg4 was best. } (16. Qg4 f5 17.Qg3 Kf6 18.Rxe6+ Bxe6 19.Qe5+ Kg6 (19...Kxg5 20.Qxg7+ Kh5 21.g4+ fxg4 22.Ne4 Nf5 23.Qh7+ Nh6 24.Ng3+ Kg5 25.Qg7+ Kf4 26.Qe5+ Kf3 27.Qe3#) 20.Nxe6 Rf7 21.Nxd8 Rxd8 22.Qe6+ Rf6 23.Qxe7) 16... Nf5?? { (0.48 → 3.07) Blunder. f5 was best. } (16... f5 17. Qd3) 17. Qg4 Nh6?? { (3.02 → 18.38) Blunder. Kh6 was best. } (17... Kh6 18. Qf4) 18. h5+ Kf6 19. Nh7+ Ke7 20. Qxg7 Nf5 21. Qf6+ Kd7 22. Nxf8+ Qxf8 23. d5 Qe7 24. dxe6+ fxe6 25. Rad1+ Ke8 26. Qg6+ Kf8 27. Nd5?! { (8.95 → 5.75) Inaccuracy. g4 was best. } (27. g4 Bd7) 27... Qf7 28. Qxf7+?! { (5.81 → 4.44) Inaccuracy. Nc7 was best. } (28. Nc7 Qxg6 29. hxg6 Rb8 30. Rd8+ Ke7 31. Rd5 Nh4 32. Rg5 Bd7 33. Nd5+ Kd6 34. Nf6 Ke7) 28... Kxf7 29. Nc7 Rb8 30. g4 Nh6?! { (4.29 → 6.18) Inaccuracy. Nh4 was best. } (30... Nh4 31. Rd3) 31. g5 Nf5 32. Rd8?! { (4.68 → 3.44) Inaccuracy. g6+ was best. } (32. g6+ Kf6 33. Rd8 Nc6 34. Rf8+ Kg5 35. g7 Nxg7 36. Rg8 e5 37. Rxg7+ Kh6 38. Rg6+ Kh7) 32... Nc6 33. Rh8 Kg7 34. Re8 Nd6?? { (2.92 → 6.87) Blunder. Nfd4 was best. } (34... Nfd4 35. Kg2) 35. Nxe6+ Bxe6 36. R8xe6 Rd8 37. Rg6+ Kh7 38. Ree6 Nf5 39. Rgf6?! { (5.78 → 4.01) Inaccuracy. Ref6 was best. } (39. Ref6) 39... Nfd4? { (4.01 → 8.84) Mistake. Ncd4 was best. } (39... Ncd4 40. Rf7+ Kg8 41. Ref6 Nf3+ 42. Kf1 Nxg5 43. Rxb7 Nh4 44. Rxa7 Nhf3 45. Rb6 Re8 46. Kg2) 40. Rh6+ Kg7 41. Reg6+ Kf7 42. Rh7+ Kf8 43. Rgg7 Ne5 44. h6 Nf5? { (9.06 → Mate in 1) Checkmate is now unavoidable. Ndf3+ was best. } (44... Ndf3+ 45. Kg2 Nh4+ 46. Kf1 Neg6 47. Rxb7 Kg8 48. Rbg7+ Kf8 49. Rxa7 Kg8 50. Rhf7 Nf8 51. f4) 45. Rh8# { White wins by checkmate. } 1-0Nice game. I'm glad I got the basics correct, but I can't take too much credit - I got most of it from Vukovic, whose book I highly recommend. In a rapid game, I would definitely play the sacrifice, as it's very hard to defend accurately with limited time (as we can see from the game).

Desmond
06-07-2020, 10:32 AM
Nice game. I'm glad I got the basics correct, but I can't take too much credit - I got most of it from Vukovic, whose book I highly recommend. In a rapid game, I would definitely play the sacrifice, as it's very hard to defend accurately with limited time (as we can see from the game).

Thanks.

Yes I think it's a good general rule, though my position was a little different. I didn't have the pawn on e5 and the DSB I already used to lure the knight away from f6.

I think Q + 2 pieces is certainly enough. I've seem to recall reading some book where it said you could count the pawn on e5 as a "piece" in that sense, because it's keeping the king in but also importantly making it harder for black to bring pieces into the defence Eg via f6.

I also think even apart from the Bxh7 sacs, counting the number of pieces you can quickly bring to the attack and the amount of defenders likewise, if you have a +3 score there for pieces, you've got a pretty goods chance there's a win there. In this case I had Q+2N+R. Black kind of had Q+N but neither could really get to ideal squares in time.

Capablanca-Fan
06-07-2020, 03:13 PM
Good intuition. The variation with 16. Qg4 is very elegant.

Desmond
23-07-2020, 06:35 PM
Svidler-Leko Legends of Chess Rd 2 Game 3 Rapid
Analysis from lichess https://lichess.org/broadcast/chess24-legends-of-chess-day-2/5QwaAsJA

22.Bxh7+ Kxh7 23.Qh5+ Kg8 24.fxe5 g6 [??Blunder. Rc7 was best.
24...Rc7 25.exd6 Qxd6 26.Qg4 Qg6 27.Qxg6 fxg6 28.Rxa5 Nd5 29.Ba1 b4 30.Rc1 Rd8 31.Rcxc5]
25.Qf3?? [Blunder. Qh3 was best.
25.Qh3 Bxe5 26.Rxf7 Kxf7 27.Qh7+ Kf8 28.Rf1+ Qf6 29.Rxf6+ Bxf6 30.Bxf6 Re6 31.Qb7 Rxf6]
25...f5 26.exd6 Re4 27.Qg2 Nd5?? [Blunder. Rd8 was best. 27...Rd8 28.Qh3] 28.d3 Nxc3 29.dxe4 Nxe4 30.g4 c4? [Mistake. Nxd6 was best. 30...Nxd6 31.gxf5] 31.gxf5 Qxe3+ 32.Kh1 1-0

Desmond
11-01-2021, 09:10 PM
Quite a nice game by Dubov in recent Banter Blitz, but with a twist - the sac on h7 was an empty square, with the pawn already on h6!
https://chess24.com/en/game/AdnQeLNdQGyQDI1C-Mr7LQ

1. d4 Nf6 2. Nf3 e6 3. Bg5 Be7 4. Nbd2 d5 5. e3 O-O 6. Bd3 h6 7. Bf4 c5 8. c3 Nc6 9. O-O Re8 10. Ne5 Nd7 11. Bh7+ Kxh7 12. Nxf7 Qb6 13. Qc2+ Kg8 14. Nxh6+ gxh6 15. Qg6+ Kh8 16. Qxh6+ Kg8 17. Qxe6+ Kh7 18. Qf7+ Kh8 19. Qxe8+ Kg7 20. e4 Nf6 21. Be5 Nxe5 22. Qxe7+ Nf7 23. dxc5 Qxb2 24. Nf3 Bd7 25. e5 Ne4 26. Qxd7 Rd8 27. Qg4+ Kf8 28. e6 Ke7 29. exf7 Kxf7 30. Qf5+ Ke7 31. Rab1 Qxc3 32. Rxb7+ 1-0