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ElevatorEscapee
12-06-2006, 05:53 PM
This is the position that Garry W showed me a couple of weeks back:

K6k/8/3p4/8/8/2R5/3p4/3b4 w - - 0 35

White is to play.

Black is threatening to promote his pawn on d2, either by moving his Bishop to f3 checking the White king, or simply by playing the Bishop to e2, threatening to promote on the next move.

With best play, can White draw?

I thought the solution was quite clever and worth sharing here, but can anyone figure it out by themselves first? :)

Pharoah
13-06-2006, 02:29 AM
cd3?

(Did I say that right? I guess it could also be Rd3.)

It gets rid of his chance of promotion.

ElevatorEscapee
13-06-2006, 08:48 PM
Hi Pharoah, thank you for posting. :)

1.Rd3 was the first move I tried when first faced with this problem! :)

(Note that in chess notation we would only use 1.cd3 only if a pawn on the 'c' file was making a capture on d3. Where another piece is involved we use the capital letter for that piece (eg R for Rook) with the exception of "N" for Knight, as we don't want it to get confused with the King! :) ).

The trouble with 1.Rd3 however is that after:

1.Rd3 Bf3+

White is now in check, and must either move his king, or capture the bishop with his rook.

2.Rxf3 leads to an immediate 2... d2-d1=Q (Black promotes to a Queen giving him a winning endgame of King, Queen & Pawn versus King & Rook).

Moving the King on the second move is no less palatable for White, eg:

2.Ka7 d2-d1=Q
3.Rxd1 (capturing the queen) 3... Bxd1 (Black captures the rook)

Black now has a position of King, Pawn & Bishop versues a lone King. Black will be able to promote his pawn (on d3) to a Queen by keeping White's King away from the promotion square with his own King & Bishop.

That seems to rule out the first move 1.Rd3, however White has some other first moves that you might like to try. What can White do to prevent Black from promoting that pawn within the next couple of moves? :)

Desmond
13-06-2006, 09:11 PM
Further to EE's post, there is an interesting nuance in the line described.

1. Rd3 Bf3+
2. Kb8 d1=Q
3. Kc7

And now the white king is half a step behind the pawn. However the pawn cannot simply win the foot race due to the bishop needing to get out the way first. EG:

3. ... d5
4. Kd6 d4
5. Kd5 d3
6. Kd4 d2
7. Kd3 and wins the pawn next move.

I thought this worth mentioning because although it is not the solution, it may be an idea that the solution requires in some variation that I haven't thought of. Black finds the win with:

3. ... d5
4. Kd6 Bf3 -+

ElevatorEscapee
13-06-2006, 09:21 PM
Thanks Boris, but what about in your varition if after:

1.Rd3 Bf3+
2.Kb8 d1=Q
3.Kc7

Black were to play:

3... Qxd3 (capturing the rook) ? ;)

Desmond
13-06-2006, 09:24 PM
Thanks Boris, but what about in your varition if after:

1.Rd3 Bf3+
2.Kb8 d1=Q
3.Kc7

Black were to play:

3... Qxd3 (capturing the rook) ? ;)

ahem... I appear to have omited a move

3. Rxd1 Bxd1
4. Kc7 etc

To be fair, I didn't point out the mistakes in your notation ;)

ElevatorEscapee
13-06-2006, 09:36 PM
Thanks for the clarification Boris :)

In your analysis, Boris, you are of course correct, after winning the rook, Black can simply move his pawn to a white square, protect it with his Bishop (so the White king can't capture it) and bring up his own King to decide the matter. :)

I would like to apologize for any confusion I may have caused with my style of notation. By alternating between shorterened algebraic and extended algebraic I was trying to make sure that people understood the moves I was attempting to describe rather than strictly trying to adhere to one form of notation. :oops:

Desmond
13-06-2006, 09:44 PM
Thanks for the clarification Boris :)

In your analysis, Boris, you are of course correct, after winning the rook, Black can simply move his pawn to a white square, protect it with his Bishop (so the White king can't capture it) and bring up his own King to decide the matter. :)

I would like to apologize for any confusion I may have caused with my style of notation. By alternating between shorterened algebraic and extended algebraic I was trying to make sure that people understood the moves I was attempting to describe rather than strictly trying to adhere to one form of notation. :oops:

No worries, but I was more referring to Kh7 (should be Ka7 I assume) and d7-d8 (should be d2-d1) and Rxd8 (should be Rxd1) :P

Another note-worthy try is:
1. Rh3+ Kg7
2. Rg3+ hoping for Kf6(or f7/f8) when
3. Rd3 Bf3+ may be met by
4. Rxf3+

Black can of course avoid this by staying off the f-file and snaking the K up to attack the R.

ElevatorEscapee
13-06-2006, 10:32 PM
Thanks Boris, to avoid confusion to the readers I have edited my original post with your corrections. :)

You are nearly there! Now what happens when Black tries to zig-zag the King up to attack the rook? :D

Igor_Goldenberg
16-06-2006, 09:41 AM
Very difficult. I don't think I'd found it during the tournament game. Even though it seems easy after you worked it out.

Desmond
16-06-2006, 09:54 AM
Found it :D There was another theme that I hadn't noticed which lead me to the solution. Shall I post the solution or let others have a go?

Arrogant-One
16-06-2006, 01:32 PM
Further to EE's post, there is an interesting nuance in the line described.

1. Rd3 Bf3+
2. Kb8 d1=Q
3. Kc7

3. ... d5
4. Kd6 d4
5. Kd5 d3
6. Kd4 d2
7. Kd3 and wins the pawn next move.

I thought this worth mentioning because although it is not the solution, it may be an idea ...

Actually Boris, Black's move 3 would be just to take the Rook at d3 with the newly promoted pawn, and not d5.

Arrogant-One
16-06-2006, 01:38 PM
Found it :D There was another theme that I hadn't noticed which lead me to the solution. Shall I post the solution or let others have a go?

I believe I too have found it. Very clever puzzle. EE, do you want me to post the solution?

Desmond
16-06-2006, 01:42 PM
Actually Boris, Black's move 3 would be just to take the Rook at d3 with the newly promoted pawn, and not d5.

Thanks Captain Obvious ... did you notice that EE had already pointed this out and I had replied some days ago?

Arrogant-One
16-06-2006, 01:55 PM
This is the position that Garry W showed me a couple of weeks back:

K6k/8/3p4/8/8/2R5/3p4/3b4 w - - 0 35

White is to play.

Black is threatening to promote his pawn on d2, either by moving his Bishop to f3 checking the White king, or simply by playing the Bishop to e2, threatening to promote on the next move.

With best play, can White draw?

I thought the solution was quite clever and worth sharing here, but can anyone figure it out by themselves first? :)

Okay, its been up for four days so I am going to post the solution for the benefit of all BB users.

When I first looked at the problem I nearly thought I had solved it with the following variation:

1.) Rc8+ Kg7
2.) Rc7+ Kf6
3.) Rd7 Bf3+
4.) Ka7 d1=Q
5.) Rxd6+ QxR=

Stalemate.

But of course this variation only works if Black plays into Whites hand. I was unable to resolve what White could do if Black doesn't play Kf6 and instead goes for the rook the other way, ie. Kf8.

Then part of the answer came to me - Get the King on the 8th file and you don't have to worry about the pesky Bf3+ anymore. Combining this knowledge
with my first discovery I found the following solution:

1.) Rh3+ Kg7
2.) Rg3+

Now, there are two main variations. If

2.) ... Kf6 or Kf7 or Kf8 then Rd3 wins because the Bf3+ is met by RxB+, and then the Rook can go back to the d3 square

The second variation is this:

2.) ... Kh6 attempting to march the King up to confront the Rook.

But this move also loses to Rd3 because if Black now plays Bf3+, the White King goes to a7, and we get my original variation.

1.) Rh3+ Kg7
2.) Rg3+ Kh6
3.) Rd3 Bf3+
4.) Ka7 d1=Q
5.) Rxd6+

and the Queen is forced to take the Rook with a stalemate resulting.

If the Queen doesn't take the rook, and instead moves the King then Rook takes Queen next move leads to a traditional Rook v Bishop draw.

Arrogant-One
16-06-2006, 03:36 PM
Thanks Captain Obvious ... did you notice that EE had already pointed this out and I had replied some days ago?

Um, no, actually. I didn't.

Would you like me to withdraw the post so that it does not offend your delicate sensibilities?

Desmond
16-06-2006, 03:44 PM
Um, no, actually. I didn't.

Would you like me to withdraw the post so that it does not offend your delicate sensibilities?

Yes please, and the rest of your posts while you are at it. I would write more, but it appears your attention span would have already waned

Arrogant-One
16-06-2006, 04:10 PM
Yes please, and the rest of your posts while you are at it. I would write more, but it appears your attention span would have already waned

Boris, you fool! You overplayed the position and now I take your King! If you had stopped typing after the first coma you would have been given what you desired.

Now you will have nothing!

Desmond
16-06-2006, 06:11 PM
Boris, you fool! You overplayed the position and now I take your King! If you had stopped typing after the first coma you would have been given what you desired.

Now you will have nothing!

Thanks AO, I'll be sure to file this right alongside the rest of your posts.

Desmond
16-06-2006, 09:46 PM
Sorry for my part in the digression in this thread. Very nice problem and I'm glad I found the solution (even after a hint or two) :)

Arrogant-One
17-06-2006, 01:39 PM
Sorry for my part in the digression in this thread. Very nice problem and I'm glad I found the solution (even after a hint or two) :)

Yeah, you found it after I posted the answer. How Impressive is that?

Desmond
17-06-2006, 01:41 PM
Yeah, you found it after I posted the answer. How Impressive is that?

Again your attention span lets you down. If you read the posts, you would see that I offered to post the solution long before you did.

ElevatorEscapee
17-06-2006, 01:46 PM
Thank you gentlemen, you have solved the chess puzzle. :)

Rather than continuing your argument here, would you like me to post another position at this time tomorrow and see which one of you can solve it first?

Cheers,

~EE :)

Desmond
17-06-2006, 01:51 PM
Rather than continuing your argument here, would you like me to post another position at this time tomorrow and see which one of you can solve it first?

I just find it a tad weird that AO took all my hints, got to the answer after me, and still had the nerve to make his comment. Also not sure why he posted the answer when 2 people had solved it before him.

Anyway, I'd be quite happy for you to post another problem here for anyone to solve. If AO wants to compete with me, he can challege me to a game.

Arrogant-One
17-06-2006, 02:19 PM
Thank you gentlemen, you have solved the chess puzzle. :)

Rather than continuing your argument here, would you like me to post another position at this time tomorrow and see which one of you can solve it first?

Cheers,

~EE :)

A good suggestion EE. However, I am only on BB about once a day for an hour or so. As such there can be no race.

Please make it an endgame problem as they are the funnest to solve. :D

Arrogant-One
17-06-2006, 02:21 PM
If AO wants to compete with me, he can challege me to a game.

Thats the first intelligent thing I think you've ever said on BB Boris. I hope to see you at the Gold Coast Open next weekend so we can have a game or two.