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Promotion to bishop

Posted: Tue Aug 26, 2008 4:56 pm
by gregorgysi
Has anybody a good example for a pawn-promotion to bishop?
I found one yesterday in German chess-magazine "Schach".
I will post it in the next days. (Just forgot to bring it to work)
Earlier I was sure that there's NO reason for a pawn to promte to bishop.
In this game I will post it is the easiest way to win. But not the only.
It is a grandmaster game. (the one with 2600+ lost against 2400+)

Please do not post problems.
Just real games.

Posted: Wed Aug 27, 2008 12:47 pm
by gmiller
I do it all the time. It only comes up in blitz games where my opponent refuses to resign and I want to mate them with a knight and bishop.

Posted: Wed Aug 27, 2008 1:28 pm
by gregorgysi
So here is the game:


Image
Black to move


W. Baklan (2606) - H. Pham Minh (2431)
Capelle la Grande 2004

Black would like to play:
c1 followed by Qe5+, Qg3+ and Bd3+.
But 1...c1Q (or 1...c1R) is not working because of 2. Rxg7+ Kxg7 3.Qg5+ and stalemate

1...c1N would be a problem because of Rd6

So:
1...c1B
2. Qxc1 Qe5+
3. Kg1 Qg3+
4. Kf1 Bd3+
0-1

Posted: Sat Aug 30, 2008 4:51 am
by jsnyder
Kamsky played a game recently in the TAL memorial where his opponent promoted to a bishop and won. They said there was another game where a player did the same.

Posted: Sat Aug 30, 2008 7:51 pm
by sonrisante
jsnyder: I think the point to the question was not whether promoting to bishop would be sufficient, but whether promoting to queen would be detrimental whereas bishop would be beneficial.

Gregorgysi: I'm going to have to play out your scenario on a board because when I go through it mentally trying to follow your depiction, I don't see how your 1...c1Q scenario with 2. Rxg7+ Kxg7 3.Qg5+ leads to stalemate where c1B would not if white followed the same moves...[/i]

I too have always thought that Knight would be the only potential piece to provide benefit over a Queen, and then only in very strange circumstances. I would have always thought that R or B could always be sufficed through a Q.

Underpromotion in Games

Posted: Tue Sep 02, 2008 3:06 am
by joelag
When I read gregorgysi's question I recalled that I once stumbled over an appropriate web site.

I've found it again:

Underpromotion in Games by Tim Krabbé
http://www.xs4all.nl/~timkr/chess2/minor.htm

CU, Joe

Posted: Mon Sep 08, 2008 5:26 am
by gregorgysi
@sonrisante:

The difference between Q and B in the stalemate line 1...c1B 2.Rxg7+ is that after 2...Kxg7 3.Qg5+ the Bishop on c1 takes the queen so g1 is free for white's king.

@joelag:
Thank you for the link.
I should have known that Tim Krabbé has some material of it as he's specialized in chess curiosoties.

Posted: Fri Dec 19, 2008 9:56 pm
by jboger
Here's a "miniature" example of where promotion to rook is the only winning move:
Image

White to move.

If White moves the king, black plays Kg7 and then captures the pawn next move -- draw.
If White promotes to queen, stalemate -- draw.
If white promotes to bishop or knight, insufficient mating material -- draw.
If white promotes to rook, however, Black must play Kg7, then white plays Rf1 or the like and goes on to mate with king and rook vs. king.