Author: Robert Hyatt
Date: 10:27:46 10/17/01
Go up one level in this thread
On October 16, 2001 at 08:13:00, Uri Blass wrote: >Can your program see the win? > >Note that yace needs a long time to avoid Kd4 that is clearly not the fastest >way to win even if it wins because after 1.Kd4 Kd8 you get a repetition that >only humans understand and computers do not know to evaluate it as a repetition. > >Note that I analyzed this position some years ago and my conclusion was that >white can win by 1.b6 cxb6 2.a6 bxa6 3.c6 > >Yace does not understand the idea and it seems that yace's main line is leading >to draw. > >yace also cannot see deep in the pawn endgame and I wonder if avoiding qsearch >can help it. > >Tiger can get bigger depth but it does not help it to see 1.b6 in a short >time(maybe 1.Kd3 also wins but it seems to me a strange way to win when 1.b6 is >the simple way0 > >New position >[D]4k3/pppppppp/8/PPPPPPPP/4K3/8/8/8 w - - 0 1 > >Analysis by Yace 0.99.56: > >1.h6 gxh6 2.gxh6 > +- (1.75) Depth: 1 00:00:00 >1.Kd4 > +- (1.89) Depth: 1 00:00:00 >1.Kd4 h6 > +- (1.83) Depth: 2 00:00:00 >1.Kd4 g6 2.hxg6 > +- (1.64) Depth: 3 00:00:00 >1.h6 c6 2.bxc6 dxc6 > +- (1.68) Depth: 3 00:00:00 >1.h6 gxh6 2.gxh6 > +- (1.75) Depth: 3 00:00:00 >1.h6 gxh6 2.gxh6 b6 3.d6 > +- (1.55) Depth: 4 00:00:00 >1.Kd4 g6 2.hxg6 hxg6 > +- (1.64) Depth: 4 00:00:00 >1.Kd4 g6 2.fxg6 fxg6 3.h6 a6 > +- (1.64) Depth: 5 00:00:00 5kN >1.Kd4 d6 2.e6 dxc5+ 3.Kxc5 b6+ 4.Kb4 fxe6 > +- (1.43) Depth: 6 00:00:13 7188kN >1.Kd4 g6 2.fxg6 fxg6 3.h6 e6 4.d6 Kd8 5.Ke4 cxd6 > ± (1.40) Depth: 7 00:02:48 89152kN >1.h6 gxh6 2.gxh6 f6 3.d6 cxd6 4.exd6 exd6 5.b6 a6 6.cxd6 Kd8 7.Kd4 Kc8 > +- (1.41) Depth: 7 00:03:15 103181kN >1.h6 gxh6 2.gxh6 Kd8 3.Kd4 f6 > +- (1.41) Depth: 7 00:03:35 113366kN >1.e6 fxe6 2.fxe6 dxe6 3.dxe6 g6 4.h6 c6 5.b6 axb6 6.axb6 Kd8 7.Kd3 Kc8 8.Kd4 Kd8 >9.Ke5 > +- (1.42) Depth: 7 00:05:58 190458kN >1.e6 fxe6 2.fxe6 dxe6 3.dxe6 g6 4.h6 c6 > +- (1.42) Depth: 7 00:06:30 207203kN >1.e6 fxe6 2.fxe6 dxe6 3.dxe6 g6 4.h6 c6 5.b6 axb6 6.cxb6 Kd8 7.Kd4 > +- (1.53) Depth: 8 00:12:38 401266kN > >(Blass, Tel-aviv 16.10.2001) > >New position >4k3/pppppppp/8/PPPPPPPP/4K3/8/8/8 w - - 0 1 > >Analysis by Chess Tiger 14.0: > >1.e6 dxe6 2.fxe6 fxe6 3.dxe6 g6 4.hxg6 hxg6 5.Kd5 > ² (0.34) Depth: 6 00:00:00 62kN >1.Kf4 Kd8 2.d6 cxd6 3.exd6 exd6 4.cxd6 > ² (0.70) Depth: 6 00:00:00 70kN >1.Kf4 Kd8 2.Ke3 b6 3.cxb6 cxb6 4.e6 fxe6 5.axb6 axb6 6.dxe6 > = (0.20) Depth: 7 00:00:00 114kN >1.e6 dxe6 2.fxe6 fxe6 3.Ke5 exd5 4.Kxd5 a6 5.bxa6 c6+ 6.Ke6 bxa6 > ² (0.30) Depth: 7 00:00:00 131kN >1.Kd4 g6 2.c6 bxc6 3.dxc6 dxc6 4.fxg6 fxg6 5.hxg6 hxg6 6.bxc6 > ² (0.34) Depth: 7 00:00:01 183kN >1.Kd4 g6 2.c6 bxc6 3.dxc6 dxc6 4.fxg6 fxg6 5.hxg6 hxg6 6.bxc6 > ² (0.34) Depth: 8 00:00:01 238kN >1.Kd4 g6 2.fxg6 fxg6 3.hxg6 hxg6 4.d6 cxd6 5.exd6 exd6 6.Kd5 dxc5 7.Kxc5 > = (0.22) Depth: 9 00:00:02 434kN >1.Kd3 Kd8 2.Kd4 Ke8 3.Ke4 g6 4.hxg6 hxg6 5.e6 dxe6 6.dxe6 gxf5+ 7.Kxf5 > ² (0.42) Depth: 9 00:00:06 927kN >1.Kd3 Kd8 2.Kd4 Ke8 3.Ke4 g6 4.hxg6 hxg6 5.e6 dxe6 6.dxe6 gxf5+ 7.Kxf5 > ² (0.42) Depth: 10 00:00:08 1289kN >1.Kd3 Kd8 2.Kc4 Ke8 3.c6 bxc6 4.bxc6 dxc6 5.Kc5 cxd5 6.Kxd5 g6 7.fxg6 fxg6 >8.hxg6 hxg6 > ² (0.36) Depth: 11 00:00:18 2865kN >1.Kd3 Kd8 2.Kc4 Ke8 3.c6 bxc6 4.bxc6 d6 5.exd6 exd6 6.Kb5 f6 7.Ka6 Kd8 8.Kxa7 > ² (0.44) Depth: 12 00:00:35 5959kN >1.Kd3 > ± (1.34) Depth: 13 00:01:15 13213kN >1.Kd3 Kd8 2.f6 exf6 3.g6 fxg6 4.h6 gxh6 5.exf6 d6 6.b6 cxb6 7.c6 bxc6 > ± (1.35) Depth: 13 00:01:17 13613kN >1.Kd3 g6 2.e6 b6 3.axb6 axb6 4.cxb6 cxb6 5.exf7+ Kxf7 6.fxg6+ hxg6 7.h6 d6 8.Kd4 >Kf8 9.Ke3 Kf7 10.Ke4 > +- (2.24) Depth: 14 00:02:18 25407kN >1.Kd3 g6 > +- (2.24) Depth: 15 00:03:55 43907kN > >(Blass, Tel-aviv 16.10.2001) > >yace has no problem to see the win some plies after the root position > >New position >[D]4k3/p2ppppp/ppP5/3PPPPP/4K3/8/8/8 b - - 0 1 > >Analysis by Yace 0.99.56: > >3...dxc6 4.dxc6 > -+ (-1.45) Depth: 1 00:00:03 >3...g6 > -+ (-1.60) Depth: 1 00:00:03 >3...h6 > -+ (-1.62) Depth: 1 00:00:03 >3...b5 > -+ (-1.71) Depth: 1 00:00:03 >3...a5 > -+ (-1.81) Depth: 1 00:00:03 >3...a5 4.c7 b5 > ± (1.12) Depth: 2 00:00:03 >3...a5 4.c7 b5 5.c8Q# > +- (7.19) Depth: 2 00:00:03 >3...a5 4.c7 b5 > +- (7.19) Depth: 2 00:00:03 >3...g6 4.c7 gxf5+ 5.Kxf5 > µ (-0.79) Depth: 2 00:00:03 >3...dxc6 4.dxc6 > -+ (-1.45) Depth: 2 00:00:03 >3...Kd8 4.g6 > -+ (-1.49) Depth: 2 00:00:03 >3...Kd8 4.Kd4 > -+ (-1.49) Depth: 2 00:00:03 >3...Kd8 4.e6 fxe6 5.fxe6 > -+ (-1.69) Depth: 3 00:00:03 >3...Kd8 4.e6 fxe6 5.fxe6 > -+ (-1.69) Depth: 4 00:00:03 >3...dxc6 4.dxc6 a5 5.Kd5 b5 > -+ (-1.72) Depth: 4 00:00:03 >3...dxc6 4.dxc6 e6 5.fxe6 fxe6 6.Kd4 a5 7.Kc4 Kd8 8.Kb5 > -+ (-1.87) Depth: 5 00:00:04 5kN >3...dxc6 4.dxc6 a5 5.h6 gxh6 6.f6 e6 7.gxh6 b5 8.c7 Kd7 > -+ (-1.80) Depth: 6 00:00:04 274kN >3...Kd8 4.e6 fxe6 5.fxe6 dxe6 6.g6 hxg6 7.Ke3 b5 8.hxg6 a5 9.Kd4 a6 10.d6 > -+ (-1.81) Depth: 6 00:00:05 829kN >3...Kd8 4.Kd4 dxc6 5.dxc6 Kc7 6.Kd5 e6+ 7.fxe6 fxe6+ 8.Kxe6 Kxc6 > -+ (-2.26) Depth: 6 00:00:06 1343kN >3...Kd8 4.h6 gxh6 5.e6 fxe6 6.dxe6 hxg5 7.cxd7 g4 8.Ke5 g3 9.f6 g2 10.f7 g1R >11.f8Q+ Kc7 > -+ (-1.86) Depth: 7 00:00:11 3983kN >3...Kd8 4.h6 g6 5.c7+ Kxc7 6.e6 f6 7.fxg6 f5+ 8.Kxf5 > µ (-0.89) Depth: 7 00:00:13 5084kN >3...dxc6 4.dxc6 a5 5.h6 g6 6.c7 gxf5+ 7.Kf3 Kd7 8.g6 fxg6 9.c8R > µ (-0.90) Depth: 7 00:00:14 5603kN >3...dxc6 4.dxc6 a5 5.h6 g6 6.fxg6 fxg6 7.Kd3 b5 8.Kd4 Kd8 9.Kd5 > -+ (-1.93) Depth: 7 00:00:15 5603kN >3...dxc6 4.dxc6 Kd8 5.h6 e6 6.fxe6 f6 7.gxf6 gxh6 8.c7+ Kxc7 9.e7 Kd7 10.e8Q+ >Kxe8 11.e6 a5 12.f7+ Ke7 13.Ke5 > -+ (-1.53) Depth: 8 00:00:18 7087kN >3...dxc6 4.dxc6 a5 5.h6 gxh6 6.e6 Kf8 7.exf7 e6 8.fxe6 Kg7 9.f8Q+ Kxf8 10.gxh6 >Ke8 > ³ (-0.53) Depth: 8 00:00:18 7087kN >3...dxc6 4.dxc6 Kd8 5.h6 g6 6.e6 f6 7.c7+ Kc8 8.fxg6 f5+ 9.Kxf5 > ± (1.20) Depth: 8 00:00:22 9133kN >3...dxc6 4.dxc6 a5 5.h6 f6 6.exf6 a4 > +- (1.60) Depth: 9 00:00:38 17838kN >3...dxc6 4.dxc6 b5 5.h6 gxh6 6.e6 fxe6 7.f6 hxg5 8.f7+ Kxf7 9.c7 a5 10.c8Q a4 >11.Qa6 e5 12.Qxa7 h6 > +- (2.60) Depth: 9 00:00:39 17838kN >3...dxc6 4.dxc6 a5 5.h6 gxh6 6.c7 Kd7 7.g6 fxg6 8.f6 exf6 9.exf6 Kxc7 10.f7 a6 >11.f8Q h5 > +- (3.59) Depth: 9 00:00:49 22813kN >3...dxc6 4.dxc6 a5 5.f6 gxf6 6.e6 fxe6 7.g6 hxg6 8.hxg6 a4 9.c7 f5+ 10.Ke5 Kd7 >11.g7 Kxc7 12.g8Q b5 13.Qxe6 a6 > +- (3.99) Depth: 10 00:01:23 39309kN >3...dxc6 4.dxc6 a5 5.f6 gxf6 6.e6 fxe6 7.g6 hxg6 8.hxg6 a4 9.g7 > +- (4.02) Depth: 10 00:01:39 47023kN > >(Blass, Tel-aviv 16.10.2001) > >Uri To avoid a lot of calculating, I would probably try g6 first, and use the "sneaker" idea to create a passed pawn over there. Once the black king moves in that direction, b6 to do a "sneaker" on the other side is a simple win. (note "sneaker" is the name I often saw applied to the idea of playing b6. if black plays axb6 then white plays c6. If bxc6 then a6 wins. If bxa5 then cxb7 wins.) Note that I don't see an instant win with your suggestion of b6, axb6 c6, as I play dxc6 and you don't have a passer yet. At shallow searches, Crafty seems to go for e6, which will dislodge the d pawn and make the queen-side sneaker work if the king can be decoyed away. I haven't spent a lot of time looking at this, of course, so your analysis could be right for other reasons. But I don't see how b6 wins instantly as it would if the king was over one more square and the d pawn (for black) was missing.
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