Author: Uri Blass
Date: 03:52:33 12/06/04
Go up one level in this thread
On December 06, 2004 at 00:33:31, Anthony Cozzie wrote: >Every so often when Zappa and Crafty play, they come up with some really >brilliant moves and tough positions. Somehow, when I watched this game I had an >intense image of two boxers who just refused to give up, no matter how bloodied >they were. You can judge for yourself. The opening was a French defense, with >Zappa defending. Zappa had a few tense moments, but it was able to get a very >solid position, despite the horrible French bishop. Zappa thought it was about >equal, while Crafty liked white to the tune of about +0.6. I guess the true >value is somewhere in between; Black should draw but I think White has all the >winning chances here. > >[D]2r1r1k1/3bq2p/p5pQ/Pp1pPp2/3P4/3B1R2/2P3PP/5RK1 b - - 0 24 > >So they shuffled, as computers are wont to do, and Crafty was finally so happy >with its position that it gave away the a5 pawn in order to prevent the draw. >At this point Crafty was about +0.4, while Zappa thought it was winning by 0.7 >or so. The shuffling continued, with Zappa trying to advance its passed a pawn >without letting Crafty checkmate it on the kingside. > >[D]2r4k/7p/p3b1p1/qp1pPp2/3P1R2/2rB2R1/2P3PP/4Q1K1 w - - 0 38 > >Here came the first problem. Zappa had counted on Kg8, but white has a draw in >that line. > >[D]2r5/6kp/4b1p1/1p1pPp2/pq1P3Q/2rB2R1/2P3PP/5RK1 b - - 0 45; bm Qf8; test >position 1 > >1... Kg7-g8 2. Rg3-h3 Rc3-c7 3. c2-c3 Qb4xc3 4. Bd3xb5 Qc3-b4 5. Bb5-a6 Rc8-b8 >6. Rf1-e1 a4-a3 > = (1.13) Depth: 11/33 00:00:08.83 4885kN (553 KN/s, 0 splits, 0 aborts) >1... Kg7-g8 2. Qh4-f6 Rc3-c6 3. Rg3xg6 h7xg6 4. Qf6xg6 Kg8-h8 5. Qg6-h6 Kh8-g8 >6. Qh6-g6 > = (0.00) Depth: 12/33 00:00:12.63 7287kN (577 KN/s, 0 splits, 0 aborts) >1... Qb4-f8 2. Rg3-h3 h7-h5 3. Rh3-g3 Kg7-h7 4. Bd3xb5 Rc3xg3 5. Qh4xg3 Qf8-b4 >6. Qg3-d3 a4-a3 7. Rf1-f3 > = (0.56) Depth: 12/34 00:00:28.62 17188kN (600 KN/s, 0 splits, 0 aborts) > >This let Crafty win the b5 pawn, and the shuffling continued. Zappa was able to >get its a pawn to a2, but it remained hampered by its horrible bishop. Finally, >just when Crafty thought it had equalized, Zappa struck: > >[D]8/r5k1/4b1p1/1q1pPp1p/3P4/2P3P1/p4K1P/R1QB4 b - - 0 68; bm f4! test position >2 > >1... f5-f4 2. g3xf4 Be6-f5 3. Bd1-c2 Bf5-g4 4. Kf2-g1 Qb5-e2 5. Bc2-b3 Bg4-e6 6. >f4-f5 g6xf5 7. Qc1-g5 Kg7-h7 > = (1.14) Depth: 13/36 00:00:38.98 29001kN (744 KN/s, 0 splits, 0 aborts) > >After some complicated tactics, Zappa emerged with a Rook versus Crafty's 3 >passed pawns. When I was just about to celebrate a pretty win, Zappa threw the >game away with Rf4??. This is a really hard position for Zappa, because after >Rf4 d5 it has a Rook and Bishop vs 2 connected passers, whereas after Bf5 it has >a Rook vs 3 connected passers :) Crafty gets it at 8 ply or so though. > >[D]8/7k/4Prp1/7p/2BP4/2P5/7P/1b4K1 b - - 0 82; bm Bf5!; test position 3 > >After Rf4 Crafty was able to force the draw, although Zappa didn't realize it >for another 10 moves. The final position: Not a good test position. It is possible to find Bf5 for the wrong reason. Movei also needs 8 plies to find it but needs depth 13 to find Crafty's d5(still without a draw score). Note also that I expect zappa to find Bf5 after more time simply because it wins material and from computer point of view it should not be. Movei after some time has fail high on Bf5 I am also not sure if d5 force a draw and movei does not agree with capturing the bishop after d5 and suggests the line d5 Bf5 d6 Re4 At this moment of posting I see another fail high for d5 so maybe not capturing the bishop also does not help. I am surprised that zappa fail here relative to movei because I expect movei to be weak in endgame considering the fact that it does not use hash for pruning. Uri
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