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View Full Version : Which pawn? Why? Glory or tears?



Basil
19-01-2007, 05:17 PM
3r4/4k3/1p1pp1q1/pPr1p3/P3P1P1/6Pp/1K1QN2P/3R4 b - - 0 39

Black to play. Queen takes which pawn (e4 or g4) and win (somewhat trivially)? Take the wrong pawn and the match is a forced draw within but a few moves!

Guessing the right pawn to take is not entirely straight forward, but proving it is somewhat more difficult.

Answer posted in a few days. It is requested that stronger players only signal that they have the answer (as opposed to publishing it). Alternatively, publishing the answer in white text.

I found this position most instructive. Its the sort of error that I would be likely to play OTB. [Game from Possum: Axiom v Duggan, correspondence, chesschat].

MichaelBaron
19-01-2007, 05:43 PM
I am too lazy to set up the position on the chessboard and start moving pieces. but it looks like Qxe4 is no good due to a simple tactic (Qg5+ Kd7
Rxd6+).

I guess Qxg4 is stronger.:hmm:

Basil
19-01-2007, 05:59 PM
I am going to answer now, because what I have posted is not strictly accurate. Michael is correct that Qxg4 is correct (unless you enjoy swimming with crocs). The reason is to be found below:

3r4/4k3/1p1pp3/pPr1p1Q1/P3q1P1/6Pp/1K2N2P/3R4 b - - 1 40

White's 40.Qg5+ forces black to find the very difficult 40...Kf7, leaving the d8 rook en prise:

3r4/5k2/1p1pp3/pPr1p1Q1/P3q1P1/6Pp/1K2N2P/3R4 w - - 2 40

but the rook is immune as black mates with rolling checks. Psychologically very hard for some (me).

The fatal error, 40...Kd7 allows (as Michael suggested) 41.Rxd6+ 41...Kxd6 42.Qxd8 ++
Alternatively, protecting the rook with 40...Ke7 allows 41.Qg8+ forcing a perpetual check in order to avoid the aforementioned mate.

Ouch!

Kevin Bonham
19-01-2007, 06:45 PM
White's 40.Qg5+ forces black to find the very difficult 40...Kf7, leaving the d8 rook en prise:

Isn't black still then winning (albeit not convincingly) after 40...Kf7 ? After 41.Rf1+ Ke8! 42.Rf8+ (forced - White must not allow Kd7) Kxf8 White does not appear to have a perpetual even after retaking the rook.

Basil
19-01-2007, 09:02 PM
Yes black is still winning.

I haven't constructed this well. I meant to illustrate that if black stayed next to the rook, he was lost or drawn at best.

MichaelBaron
20-01-2007, 12:09 PM
I obviously saw the draw in the line other than Kd7 but i just felt no need to post it cause its obvious. It is the Rxd6 trick that could be missed

antichrist
22-01-2007, 11:29 AM
Having a quick glance at this it looks quite similar to endgame theory in Fred Reinfeld's book The Complete Chess Course - is that where it is dragged from?

Basil
22-01-2007, 11:56 AM
Having a quick glance at this it looks quite similar to endgame theory in Fred Reinfeld's book The Complete Chess Course - is that where it is dragged from?

Nope.


Game from Possum: Axiom v Duggan, correspondence, chesschat

Garrett
27-01-2007, 07:38 AM
Is this the new 'Grandmaster Theatre' Howie ?

Cool.

IM_bob
27-01-2007, 05:45 PM
What's wrong with queen takes g4?

And if Kf7 Rf1+ Ke8 what about Ke8 Qg8+? Would that be a perpetual draw?

Kevin Bonham
27-01-2007, 07:19 PM
Also, why does Black need to take a pawn at all, eg what is wrong with ...d5 ?

Basil
27-01-2007, 07:27 PM
Also, why does Black need to take a pawn at all, eg what is wrong with ...d5 ?
...d5 is good. Computer suggests it. It was one of my candidates which I rejected on account of loosening the position (throwing the opponent an anchor).

I'm starting to regret this post! :) I merely wanted to illustrate capturing either seemingly innocuous pawn had vastly different outcomes. I will double check the simplicity of my next puzzle :eek: :P