| |
Main
Date: 29 Jun 2005 09:17:18
From: Tantale
Subject: Is this position a draw?
|
7K/8/3P1p1k/8/5P2/5P2/B7/7r w - - 0 1
White : Ka8 Ba2 d6 f3 f4
Black : Ka6 Ra1 f6
White to play.
--
http://www.jmrw.com/
J'ai d�couvert que tout le malheur des hommes vient d'une seule chose, qui
est de ne savoir pas demeurer en repos dans une chambre.
Pascal (Pens�es)
|
|
| |
Date: 29 Jun 2005 16:04:52
From: =?ISO-8859-1?Q?Claus-J=FCrgen_Heigl?=
Subject: Re: Is this position a draw?
|
Tantale wrote:
> 7K/8/3P1p1k/8/5P2/5P2/B7/7r w - - 0 1
> White : Ka8 Ba2 d6 f3 f4
> Black : Ka6 Ra1 f6
> White to play.
No draw. White wins.
The idea is to reach a pawn endgame in the position
White: Kd8, f3, f4
Black: Kf6, f5
In this endgame Black can't defend his pawn.
White to move: 1. Kd7 Kf7 2. Kd6 Kf6 3. Kd5 Kf7 4. Ke5 Kg6 5. Ke6
Black to move: 1...Ke6 2. Ke8 Kf6 3. Kd7 Kf7 rest see above.
Most likely it is Black to move as White's last move would be KxRd8. If
the black king was at e6, the game would be a draw (1...Kd6).
So White has not only to promote his pawn but also keep the black king
away from e6.
1. Bb3 threat d7
1...Rh2 2. d7 Kg6+
If 2...Rd2 3. Be6 and Black can't prevent Kh8-g8-f8-e7.
3. Kg8 Rd2 4. Bc2+!
White mustn't let the black king eating the white pawns. 4. Ba4 Kf5 5.
Kf7 Kxf4 6. Bc6 Rxd7+! 7. Bxd7 Kxf3=. 4. Be6 f5 5. Kf8 Kf6 6. Ke8 Kxe6
7. d8Q Rxd8 8. Kxd8 Kd6= is the version of the pawn endgame that White
doesn't want to have!
4...f5 5. Ba4 Kf6 6. Kf8 Rd3
Only move. While keeping control of the promotion square d8 Black needs
to have the option of checking the white king if he moves to the e-file.
If 6...Rd6 7. Bc6! Rd1 8. Ke8 Re1+ 9. Be4.
7. Bc6 again preparing Be4
7...Rd6 only square from which the check is not blocked
8. Bb5 White keeps the e-file as much as possible under control.
8...Rd1 again only move
9. Ke8 Re1+ 10. Kd8
Now the threat is Kc7. Black has two move to counter that: Rc1 and Rd1
where Kc7 is met by Ke7.
a) 10...Rc1 11. Bd3 the threat again is 12. Ke8 Re1+ 13. Be4
11...Rc6
If 11...Rd1 12. Ke8! Rxd3 13. d8Q Rxd8 14. Kxd8 White has reached the
endgame he wants.
12. Bc4! White has e6 under control and the rook is restricted in his moves.
12...Rxc4 13. Ke8 check isn't possible 13...Rd4 14. d8Q and wins.
b) 10...Rd1 11. Bc4
Now the Black rook doesn't have a move on the d-file where he can keep
up the possibility of a check in the e-file. Black has to move his rook
on the first rank.
11...Rc1
If 11...Ra1 12. Bd5 and continuing as in Ra1, if 11...Rb1/Re1/Rh1 12. Kc8.
12. Bd5 Black has no moves left where he can keep up the possibility of
checking on the e-file as White has the defense Be4 and e6 is under
white control.
12...Rc5 or 12...Rd1 13. Ke8 Rxd5 14. d8Q and wins.
Claus-Juergen
|
| | |
Date: 29 Jun 2005 17:16:39
From: Tantale
Subject: Re: Is this position a draw?
|
Very nice analysis -):
This was a study of Pervakov,O KralinN - [+0310.31h8h6] 1996
The main line of their solution is :
1.Fb3 Th2 2.d7 Rg6+ 3.Rg8 Td2 4.Fc2+ f5 5.Fa4 Rf6 6.Rf8 Td3 --- 7.Fb5 ---
Td1 8.Re8 Te1+ 9.Rd8 Tc1 10.Fc4 Td1 11.Re8 Te1+ 12.Rf8 Td1 13.Fb5 Td6 14.Fc6
Td2 15.Re8 Te2+ 16.Fe4 1-0
(The ideas are about the same)
So you have prooved that 7.Fb5 is not the unique winning move since you give
7.Bc6 in your solution that I have checked.
I didn't say it was a study in my first post because this position could
arise in a real game.
On the board with about an hour on the clock do you think a good player
would find the win?
--
http://www.jmrw.com/
J'ai d�couvert que tout le malheur des hommes vient d'une seule chose, qui
est de ne savoir pas demeurer en repos dans une chambre.
Pascal (Pens�es)
|
| | | |
Date: 29 Jun 2005 22:17:14
From: =?ISO-8859-1?Q?Claus-J=FCrgen_Heigl?=
Subject: Re: Is this position a draw?
|
Tantale wrote:
> 1.Fb3 Th2 2.d7 Rg6+ 3.Rg8 Td2 4.Fc2+ f5 5.Fa4 Rf6 6.Rf8 Td3 --- 7.Fb5 ---
> Td1 8.Re8 Te1+ 9.Rd8 Tc1 10.Fc4 Td1 11.Re8 Te1+ 12.Rf8 Td1 13.Fb5 Td6 14.Fc6
> Td2 15.Re8 Te2+ 16.Fe4 1-0
> (The ideas are about the same)
>
> On the board with about an hour on the clock do you think a good player
> would find the win?
That could be. White should be quick to determine that he is not in any
way risking a loss with his strong passed pawn protected by the bishop.
So there is not much risk to play on. In the course of the solution,
White has only one difficult calculations to do, the rest is ideas.
1. Bb3
Here White has to see that 1. d7 Kg6+ 2. Kg8 Rd1 3. Be6 f5 4. Kf8 Kf6 5.
Ke8 Kxe6 6. d8Q Rxd8 7. Kxd8 Kd6 is a draw. White might discover here
that the pawn endgame was won if the black king still was on f6. There
is only one reasonable deviance and that's 1...Rd1? 2. Be6 f5 (2...Kg6
3. f5+ game over) 3. Bxf5 and it's clear Black can't do anything against
Kh8-g8-f8-e7. This calculation should be doable within a few minutes.
1...Rh2
Doesn't make a difference if this move is played first or Kg6+.
2. d7
The other candidate moves are Ba4, Be6 and Kf8. Be6 has been calculated
a move before so that costs no time to rule out. 2. Ba4 Rd2 3. d7 Kf5
and it is easy to see that no pawns can be saved after Kxf4, Rxd7 and
Kxf3. Harder is 2. Kf8 Kf5 3. Ke7 Re2+ 4. Kd7 Kxf4 5. Kc6 (5. Bd5 Ke5
and after Rd2 the d-pawn will fall) 5...Rd2 (5...Kxf3?? 6. Bd1) 6. Bd5
Rc2+ (6...Ke5? 7. f4+! Kxf4 8. d7) 7. Kd7 Ke5 and again the d-pawn will
fall after Rd2. White also should see that he can prevent this after
2...Kg6+ 3. Kg8 Rd2 4. Bc2+. This calculation is a bit lengthy and could
be where White fails.
The rest doen't require much calculations, just the idea that White can
sacrifice the bishop if he can promote the pawn and that he needs a
means to counter checks in the e-file by way of Be4.
Claus-Juergen
|
| | | | |
Date: 30 Jun 2005 05:54:07
From: Tantale
Subject: Re: Is this position a draw?
|
thanks.
--
http://www.jmrw.com/
J'ai d�couvert que tout le malheur des hommes vient d'une seule chose, qui
est de ne savoir pas demeurer en repos dans une chambre.
Pascal (Pens�es)
|
|
