Author: Miguel A. Ballicora
Date: 13:21:19 06/27/02
Go up one level in this thread
On June 27, 2002 at 14:53:55, John Merlino wrote: >On June 27, 2002 at 13:38:32, Ferdinand S. Mosca wrote: > >> >>The king and pawn game is a very interesting exercise to program, is it >>difficult to perfect this ending?. >> >>How long will it take your favorite programs to see that 36. h5 is good for >>black. >>[D]8/k6p/8/2P2p2/2P1p3/7K/1P3P2/8 b - - 0 35 >>sample program analysis on Athlon xp 1600+, 64MB hash >>Analysis by Gromit 3.8.2: >> >>36...h5 37.Kg3 Kb7 38.b3 Kc7 39.b4 Kc6 40.f4 Kc7 41.b5 Kb7 42.c6+ Kb6 43.c5+ Kc7 >>44.Kh3 e3 45.Kg3 h4+ 46.Kg2 h3+ 47.Kf3 >> ± (1.09) Depth: 18 00:10:55 >>36...h5 >> ± (1.09) Depth: 19 00:10:55 >>36...h5 >> ± (1.09) Depth: 19 00:11:09 >> >>more than 11 min, and yet the score still favors white. >> >> >>Analysis by Green Light Chess 2.18: >> >>36...h5 37.Kg3 Kb7 38.b4 Kc6 39.f4 Kc7 40.b5 Kd7 41.c6+ Kd6 42.Kf2 h4 43.Kg2 e3 >>44.Kf3 h3 45.Kxe3 h2 46.c5+ Kxc5 47.c7 Kxb5 48.c8Q h1Q 49.Qxf5+ >> ± (1.27) Depth: 19 00:03:16 154355kN >>36...h5 37.Kg3 Kb7 38.b4 Kc6 39.f4 Kc7 40.b5 Kd7 41.c6+ Kd6 42.Kf2 h4 43.Kg2 e3 >>44.Kf3 h3 45.Kxe3 h2 46.c5+ Kxc5 47.c7 Kxb5 48.c8Q h1Q 49.Qxf5+ >> ± (1.27) Depth: 19 00:03:17 155502kN >> >>still favors white. >> >>Regards, >>Dinan > >Chessmaster 9000 chooses h5 after three seconds, but still believes White is >winning after several minutes: > >Time Depth Score Positions Moves >0:00 2/6 2.17 2478 1...Kb7 2.b4 Kc6 3.Kh4 f4 4.Kg4 >0:00 3/7 3.10 6394 1...Kb7 2.Kg3 Kc6 3.b4 Kd7 4.Kf4 > Ke6 5.b5 >0:00 4/8 2.99 13077 1...Kb7 2.Kg3 Kc6 3.b4 Kd7 4.Kf4 > Ke6 5.b5 h5 >0:00 5/9 3.19 19013 1...Kb7 2.Kg3 Kc6 3.b4 Kd7 4.b5 > Ke6 5.c6 Kd6 6.Kf4 >0:00 6/10 2.14 43284 1...Kb7 2.b4 h5 3.b5 f4 4.c6+ Kc7 > 5.Kg2 e3 6.Kf3 exf2 7.Kxf2 h4 8.c5 >0:01 7/11 2.22 72473 1...Kb7 2.Kh4 Kc6 3.Kg5 Kxc5 4.b3 > f4 5.Kxf4 Kd4 6.c5 Kxc5 7.Kxe4 >0:01 8/12 2.89 133419 1...Kb7 2.Kh4 f4 3.Kg4 e3 4.fxe3 > fxe3 5.Kf3 h5 6.Kxe3 h4 7.b4 h3 >0:03 8/12 1.71 316053 1...h5 2.Kg3 Kb7 3.b4 Kc6 4.f4 > exf3ep 5.Kxf3 h4 6.Kf2 f4 7.Kg2 >0:05 9/13 1.91 505001 1...h5 2.Kg3 Kb7 3.b4 Kc6 4.f4 > exf3ep 5.Kxf3 h4 6.Kf4 Kc7 7.b5 h3 >0:14 10/14 1.87 1210094 1...h5 2.Kg3 Kb7 3.b4 Kc6 4.f4 > exf3ep 5.Kxf3 h4 6.Kf4 Kc7 7.b5 > h3 8.b6+ Kb7 >0:30 11/15 2.19 2537703 1...h5 2.Kg3 Kb7 3.b4 Kc6 4.f4 > exf3ep 5.Kxf3 h4 6.Kf4 Kc7 7.b5 > Kb7 8.c6+ Kc7 9.c5 h3 >1:37 12/16 1.94 7960434 1...h5 2.Kg3 Kb7 3.b4 Kc6 4.f4 > Kc7 5.b5 Kb7 6.c6+ Kb6 7.Kg2 h4 > 8.Kf2 h3 9.Kg3 e3 >4:14 13/17 1.93 20726457 1...h5 2.Kg3 Kb7 3.b4 Kc6 4.f4 > Kc7 5.b5 Kb7 6.c6+ Kb6 7.Kf2 h4 > 8.c5+ Kc7 9.Kg2 e3 10.Kf3 h3 >15:01 14/18 1.61 71024288 1...h5 2.Kg3 Kb7 3.b4 Kc6 4.f4 > Kc7 5.b5 Kb7 6.c6+ Kb6 7.Kh4 Kc7 > 8.Kh3 e3 9.Kg2 h4 10.Kf1 h3 11.c5 > >How can Black possibly win (or even draw) this game? After Kg3, White is zugswang in the king side. If f4 or h4 is allowed, white is toasted. So, it is a matter for the black king to manoeuver until it takes all white pawns. If white plays f4, it is just to delay the agony because white remains zugswang: h4 cannot be allowed and if white plays Kh3 or Kh4, e3 wins. Interestingly, all this might take few seconds for a strong human to see. Miguel > >jm
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