25 Mar 06
1 edit
Originally posted by Wulebgrc4! and Black is in zugswag. haha nice spelling.
White's move
[fen]8/8/8/2p1r3/4k1K1/2P5/2PR4/8 w - - 0 1[/fen]
Evaluate.
(from Dvoretsky's Endgame Manual)
Rook can't move along the e file because of a rook check picking up the rook. Same thing happens if he moves along the rank.
King can't really move. If Ke3 then Rd5 trading of rooks and winning or picking up the pawn with a probable win.
25 Mar 06
Originally posted by RahimK1.c4 fails because after 1...Ke3 2.Rd5, black has 2...Re4+ followed by 3...Rxc4 =
c4! and Black is in zugswag. haha nice spelling.
Rook can't move along the e file because of a rook check picking up the rook. Same thing happens if he moves along the rank.
King can't really move. If Ke3 then Rd5 trading of rooks and winning or picking up the pawn with a probable win.
25 Mar 06
It is a matter of when to exchange rooks to obtain king opposition, not about zugzwang. White plays 1.Rd1!
It is clear that the black king cannot move without losing the rook.
The black rook has only one move that doesn't lose immediately:
1. ... Re6. But then 2.Re1+ Kd5 3.c4+ Kd6 4.RxR+ KxR 5.Kf4 wins.
The other move black can try is c4. But then also 2.Re1+ Kd5 3.RxR+ KxR 3.Kg5 gains the opposition and wins.
25 Mar 06
Originally posted by Mephisto2yeah. feel happy now?
It is a matter of when to exchange rooks to obtain king opposition, not about zugzwang. White plays 1.Rd1!
It is clear that the black king cannot move without losing the rook.
The black rook has only one move that doesn't lose immediately:
1. ... Re6. But then 2.Re1+ Kd5 3.c4+ Kd6 4.RxR+ KxR 5.Kf4 wins.
The other move black can try is c4. But then also 2.Re1+ Kd5 3.RxR+ KxR 3.Kg5 gains the opposition and wins.
25 Mar 06
1 edit
Originally posted by Mephisto2Black is in zugzwang after 1.Rd1!
It is a matter of when to exchange rooks to obtain king opposition, not about zugzwang. White plays 1.Rd1!
It is clear that the black king cannot move without losing the rook.
The black rook has only one move that doesn't lose immediately:
1. ... Re6. But then 2.Re1+ Kd5 3.c4+ Kd6 4.RxR+ KxR 5.Kf4 wins.
The other move black can try is c4. But then also 2.Re1+ Kd5 3.RxR+ KxR 3.Kg5 gains the opposition and wins.
Your line continues 1... Re6 2.Re1+ Kd5 3.c4+ Kd6 4.Rxe6+ Kxe6 5.Kf4
But now black plays 5...Kf6, and black has the opposition.
Opposition is useful only when outflanking is possible. Here white has the continuation 6.Ke4 Ke6. Black still has the opposition, but white can kill a tempo:
7.c3! The point of white's third move. Again, black is in zugzwang.
25 Mar 06
Originally posted by WulebgrOf course it is the tempo with c3 that allows white to take over the opposition. I thought that was clear. And although the opposition theme is including (based on) zugzwang, it is a theme on its own.
Black is in zugzwang after 1.Rd1!
Your line continues 1... Re6 2.Re1+ Kd5 3.c4+ Kd6 4.Rxe6+ Kxe6 5.Kf4
But now black plays 5...Kf6, and black has the opposition.
[fen]8/8/5k2/2p5/2P2K2/8/2P5/8 w - - 0 6[/fen]
Opposition is useful only when outflanking is possible. Here white has the continuation 6.Ke4 Ke6. Black still has the opposition, but white can kill a tempo:
7.c3! The point of white's third move. Again, black is in zugzwang.
25 Mar 06
Originally posted by WulebgrOpposition does include zugzwang, of course, but is is much more specific and therefor a theme on its own. I would not call 1.Rd1! a zugzwang move for that reason. I thought the tempo with c3 was obvious enough (on the 7.th or even the 8th move - after Ke4 Ke6 - btw.).
Black is in zugzwang after 1.Rd1!
Your line continues 1... Re6 2.Re1+ Kd5 3.c4+ Kd6 4.Rxe6+ Kxe6 5.Kf4
But now black plays 5...Kf6, and black has the opposition.
[fen]8/8/5k2/2p5/2P2K2/8/2P5/8 w - - 0 6[/fen]
Opposition is useful only when outflanking is possible. Here white has the continuation 6.Ke4 Ke6. Black still has the opposition, but white can kill a tempo:
7.c3! The point of white's third move. Again, black is in zugzwang.
25 Mar 06
Originally posted by Mephisto2The point of gaining the opposition is to put the opponent in zugzwang so that outflanking becomes possible. RahimK had the right idea, you found the moves.
Opposition does include zugzwang, of course, but is is much more specific and therefor a theme on its own. I would not call 1.Rd1! a zugzwang move for that reason. I thought the tempo with c3 was obvious enough (on the 7.th or even the 8th move - after Ke4 Ke6 - btw.).
The position itself comes from a section titled "Zugzwang" in the chapter "General Endgame Ideas" in Dvoretsky's Endgame Manual. Dvoretsky states that black is in zugzwang after 1.Rd1. I think he is correct.
25 Mar 06
Originally posted by WulebgrI have the utmost respect for Dvoretski, may that be clear.
The point of gaining the opposition is to put the opponent in zugzwang so that outflanking becomes possible. RahimK had the right idea, you found the moves.
The position itself comes from a section titled "Zugzwang" in the chapter "General Endgame Ideas" in Dvoretsky's Endgame Manual. Dvoretsky states that black is in zugzwang after 1.Rd1. I think he is correct.
But telling that 1.Rd1 puts black into zugzwang, would mean that if after 1.Rd1, white were to move, th endgame would not be won by white, right? Well, this is NOT true. In the position AFTER 1.Rd1, if white were on the move, "c4" would win the game.
25 Mar 06
Originally posted by Mephisto2Nonsense. Your argument makes sense only when the players are in reciprocal zugzwang. In the position given, only black is in zugzwang after 1.Rd1. If black were on move in the original position, 1...Ke3 would draw.
I have the utmost respect for Dvoretski, may that be clear.
But telling that 1.Rd1 puts black into zugzwang, would mean that if after 1.Rd1, white were to move, th endgame would not be won by white, right? Well, this is NOT true. In the position AFTER 1.Rd1, if white were on the move, "c4" would win the game.
25 Mar 06
Originally posted by WulebgrWhat? So, the starting position is a zugzwang because if white were on the move it would be draw? Very, very funny.
Nonsense. Your argument makes sense only when the players are in reciprocal zugzwang. In the position given, only black is in zugzwang after 1.Rd1. If black were on move in the original position, 1...Ke3 would draw.
End of discussion.