Author: Tony Werten
Date: 01:49:55 12/04/05
Go up one level in this thread
On December 03, 2005 at 12:27:56, Robert Hyatt wrote: >On December 03, 2005 at 11:12:23, chandler yergin wrote: > >>New game >>[D]3Q4/bp3pp1/6k1/8/7R/6p1/B2p1PP1/q1rn2K1 w - - 0 1 >> >>Analysis by Shredder 8: >> >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 10/10 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 26kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 26kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 26kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 26kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 26kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 12/12 00:00:00 26kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 13/13 00:00:00 41kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 14/14 00:00:00 75kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 15/15 00:00:00 153kN >>1.Qd3+ f5 2.Qxg3+ >> +- (#14) Depth: 16/16 00:00:00 247kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Qxd2 >> +- (#11) Depth: 17/18 00:00:01 596kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ >> +- (#14) Depth: 18/54 00:07:23 166686kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 19/55 00:07:28 169067kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ >> +- (#14) Depth: 20/53 00:07:35 171711kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 21/56 00:07:42 174826kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 22/36 00:07:49 178326kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 23/38 00:08:03 184315kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 24/40 00:08:26 194168kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 25/43 00:08:56 207920kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 26/43 00:09:43 229005kN >>1.Qd3+ f5 2.Qxg3+ Kf6 3.Qd6+ Kg5 4.Rh5+ Kxh5 5.Bf7+ Kg5 6.Qg3+ Kf6 7.Qg6+ Ke5 >>8.Qe6+ Kf4 9.g3+ Kg4 10.Qg6+ Kf3 11.Qxf5+ >> +- (#14) Depth: 27/41 00:11:01 263041kN >> >>(, MyTown 03.12.2005) >> Which is what I said; deeper search confirms. >>I see no Bug, the Program found a Mate in 11 in .01 seconds >>I cut the analysis short. My error, not the Program. > > >You may not see the bug, or you may not understand the bug. But it is >absolutely a bug. > >Pick up _any_ AI textbook. Alpha/Beta is _guaranteed_ to return the same score >as a pure minimax search, only far faster. If a minimax search says "mate in >11", and there is no mate in 11 present, then that is a bug, nothing more, >nothing less. Many programs will find a mate that is sub-optimal (longer) but >if one finds one that is shorter than can be forced, it is simply a bug. Why would checkmate scores have to be exact ? You can choose to return (heuristic)checkmate scores from eval, with some bound on iteration depth. Tony > >It is time to move on...
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