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Basil
20-02-2009, 12:55 AM
White has just recaptured (24. exf4). Black to play. Who stands better in this apparently even-ish symmetrical-ish position? Why?

No 'puters. Answers in white text pliss. Go!
Oh, and it was a Tromp BTW ;)

1k1r3r/p1q5/1p1b1p2/1Pp2b1p/P1P1pP2/6P1/2Q1BB1P/R4RK1 b - - 0 24

MichaelBaron
20-02-2009, 06:23 AM
;)

road runner
20-02-2009, 08:28 AM
White will attack down the a-file, Black down the h-file. Difficult to see much play in the centre, with each side' bishop pair able to cover all the entry points for rooks.

White to play, I would play 24.h4, and build a defence on the g3 pawn while simultaneously pushing the attack down the queenside. Black does not have the corresponding resource on the other side.

But I believe from the fen viewer it is Black to play? 24...h4. If white does not capture the pawn, eg 25.a5 then 25...Qh7 looks very strong with the dual threat of 26...e3 and also nastiness on the h-file.

Buggered if I know who is better. I'd probably favour Black because he has the move and that can be all it takes in such positions.

Spiny Norman
20-02-2009, 08:33 AM
My instincts say Black is slightly better. But I can't be certain why that might be. Perhaps its that Black's bishops look more effective than White's in terms of mounting an attack on the king. But both sides look like they will attack on the side away from their king ... both can use a pawn lever to try to crack open their opponent's position (a5/h4 respectively).

Aaron Guthrie
20-02-2009, 09:32 AM
Black looks a whole lot better. Semi-open g file, h pawn, Bxf4 option, e3 option. I also like the look of Bxf4 right away, but I'm not going to calculate it now.

Ian Rout
20-02-2009, 03:35 PM
At a quick look Black looks better because White's Bishops are restricted, hence he can't throw as much stuff into following up an attack down the a-file as Black can direct at White's King (plus Blacks's e-pawn can contribute and he has the g-file).

That's just handwaving and analysis may show the opposite - are you going to tell us White won?

Garrett
20-02-2009, 04:03 PM
I *still* think Sam Fox is hot.

Basil
20-02-2009, 09:15 PM
Last call! Anyone else want a shot at glory?

ER
21-02-2009, 01:45 AM
ok my gut feeling is that Black gets there faster. I would start the attack by blocking the h2 Pawn by ... Bh3, then continue with the Pawnstorm aided by virtually all the Black pieces. (If need be sacrifice a couple of pieces ie ... Bxf4to get there) Black must win this!

Plus vehemently objecting Michael's winking smiley! It might denote suggestion of a move! :P

Ivanchuk_Fan
21-02-2009, 01:49 PM
An interesting position - White is several moves off generating any sort of an attack, whilst Black has the promising idea of ...h4, perhaps followed by ...Bh3, swinging a rook to the g-file and possibly even a ...Bf4 sacrifice if White is careless.

24...h4 is crying out to be played. Not 24...Bh3, due to 25.Qe4! Bf1 26.Bf3 Kc8 27.Rf1 when White has complete light-square dominance and a useful pawn for the exchange.

After 24...h4, 25.g4?! Bg4 26.Bg4 (26.Qe4 Rde8) Rhg8 27.Qe4 (27.h3 f5) Rg4 28.Kh1 Rf4 leaves Black a solid pawn up. 25.Bf3? also fails, this time to 25...Qh7 when moving the f3-bishop runs into the discovered attack 26...e3.

White's best defence may well be 25.Kh1, although 25...hg3 26.Bg3 Rdg8 27.Qc3 Qg7 with a strong attack still looks quite problematic for White.

Basil
21-02-2009, 07:09 PM
The bishop sac wins!

OK, apparently most of you (who answered) can assess! On this occasion, I couldn't. Not only did I (white) walk around the tournament hall waiting for my full point (part of this might have been psychological given my 700 point rating point advantage - naughty Daddy) at this point in the game, I also commented to my opponent that the bishop sac was one of the most unsound I had seen in our brief after match chat.

I am a patzer. Out and proud.

The bishop sac is crushing if, and I stress if, the correct follow-up is found.

Here is the actual game - a drifting Tromp without much of a plan.

1. d4 d5 2. Bg5 Nd7 3. Nf3 Ngf6 4. Nbd2 b6 5. Ne5 Nxe5 6. dxe5 Nd7 7. f4 Bb7 8.
e3 Nc5 9. Bb5+ c6 10. Be2 Qc7 11. O-O O-O-O 12. c3 f6 13. exf6 exf6 14. Bh4 Bd6
15. b4 Ne4 16. Nxe4 dxe4 17. Qa4 Kb8 18. Bf2 Bc8 19. c4 c5 20. b5 g5 21. g3 h5
22. Qc2 Bf5 23. a4 gxf4 24. exf4 Bxf4 25. gxf4 Qg7+ 26. Kh1 Bh3 27. Rg1 Qb7 28.
Be3 f5 29. Rad1 Rdg8 30. Qc3 Bg4 31. Qe5+ Ka8 32. Bxg4 hxg4 33. Rg3 Qh7 34.
Qd5+ Kb8 35. Qd6+ Ka8 36. Bg1 Qh4 37. Qc6+ Kb8 38. Rd7 1-0

Jesper Norgaard
16-07-2009, 08:26 AM
The bishop sac wins!
The bishop sac is crushing if, and I stress if, the correct follow-up is found.

I wonder why nobody posted a solution to the crushing follow-up, not even Gunner, but let me give it a try. With 25...Rhg8+! (Rd8 is needed there to prevent Qd5) 26.Kh1?,e3!! 27.Qxf5 (accepting all sacrifices in 1800-gentleman style) 27...Qb7+ Gunner is winning in grand style and deserves his brilliancy prize. However, I think the Bishop sac is only crushing in year 1800. Against a silicon monster or a reasonable opponent, first bailing out with 25.a5 or 25.Be1 pinning the two Bishops need consideration and no crushing is apparent and also a variation to consider is to give back material with 25.gxf4,Rhg8+ 26.Bg3,h4 27.Ra3 where White is not mated or behind in material yet.

Computer update: accepting the sacrifices is not that convincing after all for Black, Fritz gives 3 points advantage after 26.Bg3,h4 27.Ra3,Qh7! but only two point advantage after 26.Kh1!,e3!! 27.Qxf5,Qb7+ 28.Qd5,Rxd5 29.Bf3!,exf2 30.Bxd5,Rg1+ 31.Rxg1,fxg1Q+ 32.Rxg1,Qe7 and now the smoke has cleared it seems that the Queen should win against the Rook and Bishop, but White has real chances of setting up a fortress with the strong Bd5, for instance with f5 and Be6.

I must admit I did not even consider Bxf4 in the first place, presumably because Black has so many other pleasant possibilities that you don't want to crash-and-burn with a sacrifice if it is not clear. But 24...Bxf4 was objectively the best move. Still against a relatively weaker opponent I would expect to win 8 or 9 out of 10 with the simple 24...h4!? because White has no counterplay. If your opponent is continuing with a bad plan, you should not disturb him with sacrifices let him finish the job of entangling himself :lol:

Basil
16-07-2009, 10:47 AM
Hi Jesper, just passing through but ...


I wonder why nobody posted a solution to the crushing follow-up, not even Gunner...
Naughty Gunner!


... Gunner is winning in grand style and deserves his brilliancy prize
No, Gunner is white and deserved to be punished by the 'brilliancy'.


However, I think the Bishop sac is only crushing in year 1800. Against a silicon monster or a reasonable opponent, first bailing out with 25.a5 or 25.Be1
IIRC white MUST refuse the sac and then is only slightly worse with a wedge against him that (with best play) just gets bigger and bigger.


Computer update...
Thank you. Anyone else?

Jesper Norgaard
16-07-2009, 01:29 PM
IIRC white MUST refuse the sac and then is only slightly worse with a wedge against him that (with best play) just gets bigger and bigger.

Hi Gunner. You say that sac must be refused but actually accepting it all the way and giving Queen for Rook and Bishop is probably best try. Often Bishop can be sacrificed on the last pawn to get a fortress with Rook and pawn against Queen as one option - at least you can put up stiff resistance for quite some moves in the B+R vs. Q position. Not all Computer analysis, just my bid of common sense White has problems no matter what after 24...Bxf4! Also surprisingly few players know how to maneuver and win a plain Q vs. R position. I have blown it several times against Fritz' defense. You have to squiggle some tedious maneuvers with repetitive zugzwang - threats and checks do not work.

Of course you got the emergency escape after 25...Qg7+? :rolleyes:

Basil
16-07-2009, 01:38 PM
Hi Gunner. You say that sac must be refused
I did say that but I had intended to illustrate a deference to your more in-depth analysis with my following comment.