Author: Heiner Marxen
Date: 08:25:17 07/23/01
Go up one level in this thread
On July 23, 2001 at 10:10:41, Uri Blass wrote: >On July 23, 2001 at 09:50:27, Heiner Marxen wrote: > >>On July 23, 2001 at 02:25:50, Uri Blass wrote: >> >>>On July 22, 2001 at 22:44:46, Heiner Marxen wrote: >>> >>>>On July 21, 2001 at 15:02:43, Uri Blass wrote: >>>> >>>>4k3/8/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - acn 718366; acs 8; bm e4; ce 32756; dm 6; >>>>pv e4 Kf8 Qg4 Ke8 Qg7 Kd8 Bb5 Kc8 Bc6 Kd8 Qd7#; >>> >>>Here chest is faster than chessmaster in finding the shortest mate. >> >>:-) >> >>>chessmaster6000 cannot see mate in 6 even after some minutes because of null >>>move pruning unless I asked it to search for mate in 6. >>> >>>The problematic line from chessmaster's point of view is: >>>1.e4 Kd7 2.Qg4+ Kc7 3.Qg7+ Kc6 4.d4 Kb6 5.Qd7 when black is in zunzwang. >>> >>>Usually chessmaster is faster than chest in finding the shortest mate but it >>>does not know that the mate that it found is the shortest mate. >> >>Yes, and this is what makes Chest slow, most of the time: proving that all >>those shorter mates do not exist. >> >>>I guess that the times of chest in every problem is for finding all the >>>solutions and in this case chessmaster has a clear advantage because it is happy >>>with finding 1 solution. >> >>Normally (for Chest that is with composed chess problems with just one >>solution) this is not a big thing. The average solution time would reduced >>by a factor of 2, or even less, since the non-solution moves often are >>significantly faster to compute. >> >>Here, where we have 2 or sometimes even 5 solution moves, it could be a >>factor of 4. That would change the times significantly. >>OTOH, it is nice to know all solutions as a reference point. > >Yes >Chessmaster6000 had no error in the first move > >> >>>Chessmaster results in finding the shortest mate in the same problems in >>>comparison to chest: >>> >>>-, 8 >>>4, 190 >>>2, 180 >>>2, 129 >>>13, 141 >>>4, 157 >>>17, 128 >>>6, 182 >>>2, 182 >>>52, 250 >>>25, 203 >>>108,278 >>>125,178 >>>- ,186 >>>24 ,216 >>>6, 291 >>>38, 197 >>>87, 179 >>>5, 230 >>>25, 213 >>>19, 200 >>>103,357 >>>71 ,324 >> >>Thanks for the info! >>That doesn't look bad for Chest. What CPU/memory did you use for Chessmaster? > >PIII850(128 Mbytes hash tables) Thanks! So the times are (very) roughly comparable to my K7/600. >>>Chessmaster also found mate in 8 in all the other problems that were posted >>>except one >>> >>>[D]4k3/pp2p3/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1 >> >>That one is still busy computing :-) > >Chessmaster's results >e3 13 seconds: mate in 13 >e3 17 seconds: mate in 11 >e3 61 seconds: mate in 9 > >Regards,Uri Chest just completed the above position: 6851.09 sec (114.2 min) (1.9 hrs) It is a mate in 8 with 3 solution moves: e3, e4, d4: PV: e3 e6 Qh5+ Kd8 Nc3 b6 Ne4 e5 Qh7 b5 Nc5 Ke8 Bxb5+ Kf8 Ne6# PV: e4 e6 Qh5+ Kd8 h4 e5 Nc3 b6 Nd5 b5 Bxb5 Kc8 Bc6 a6 Qe8# PV: d4 e6 g3 b6 e4 e5 Bb5+ Kf8 Qf3+ Kg8 Bc4+ Kh8 Qf6+ Kh7 Qh6# Regards, Heiner
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