Author: John Merlino
Date: 11:12:31 02/16/03
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On February 16, 2003 at 11:14:56, Uri Blass wrote: >On February 16, 2003 at 11:01:49, Roy Brunjes wrote: > >> >>In a game between Fritz 8 and a custom personality of mine for CM9000, the >>following position arose in a 15/10 game: >> >>[D] 5Q2/8/2p4k/1p1pP3/8/6KP/8/q7 b - - 0 45 >> >>Black here should easily draw with ... Kh7. Fritz 8 thinks for almost 30 >>seconds on my Athlon 700 MHz machine and plays ... Kh5 and scores the position >>as 0.00 expecting a draw. >> >>CM9000 immediately shows evals nearly one pawn in its favor and after a few more >>moves, Fritz shows an eval of more than 4 pawns in White's favor. >> >>Curious that Fritz would err so greatly in a simple position. Is it a bug or is >>it explainable some other way? > >No bug >Movei like many other programs also evaluates the position after Kh7 as 0.00 > >The "bug" is in chessmaster that did not know that it is a draw and won the >game. >CM9000 for some reason does not know to count material and cannot see that black >is a pawn up. > >It evaluates the unstoppable passed pawn as clearly more than one pawn. >Chessmaster "suffers" from that "bug" for year and this is one of the reasons >that it is a good program. > >Uri I had to read that a couple of times to understand what you were saying. :-) Specifically, the default personality of CM9000, on a humble P3-733, says Kh7 is a draw in less than one second. BEFORE that, at depth 5, it sees that Kh5 (its previous best move) is bad, causing it to switch to Kh7: Time Depth Score Positions Moves 0:00 1/3 0.34 1707 45...Kg6 46.Qf6+ Kh5 47.Qf7+ Kg5 48.e6 0:00 1/3 0.00 4248 45...Kh5 46.Qf7+ Kh6 47.Qf6+ Kh5 48.Qf7+ 0:00 1/4 0.00 7509 45...Kh5 46.Qf7+ Kh6 47.Qf6+ Kh5 48.Qf7+ 0:00 1/5 0.42 15150 45...Kh5 46.Qe8+ Kg5 47.h4+ Kf5 48.Qf7+ Ke4 49.Qf4+ Kd3 50.e6 0:00 1/5 0.00 17793 45...Kh7 46.Qf7+ Kh6 47.Qf6+ Kh7 48.Qf7+ 0:00 1/6 0.00 32688 45...Kh7 46.Qf7+ Kh6 47.Qf6+ Kh5 48.Qf7+ Kh6 0:01 1/7 0.00 70141 45...Kh7 46.Qf7+ Kh6 47.Qf6+ Kh5 48.Qf7+ Kh6 0:02 2/8 0.00 135240 45...Kh7 46.Qf7+ Kh6 47.Qf6+ Kh5 48.Qf7+ Kh6 After forcing Kh5: Time Depth Score Positions Moves 0:00 1/3 0.00 4135 46.Qf5+ Kh6 47.Qf6+ Kh5 48.Qf7+ Kh6 49.Qf6+ 0:00 1/4 0.00 12804 46.Qf5+ Kh6 47.Qf6+ Kh5 48.Qf7+ Kh6 49.Qf6+ 0:00 1/4 0.45 17502 46.Qe8+ Kg5 47.h4+ Kf5 48.Qf7+ Ke4 49.Qg6+ Ke3 0:00 1/5 0.00 30998 46.Qe8+ Kg5 47.h4+ Kf5 48.Qd7+ Ke4 49.Qg4+ Ke3 50.e6 Qg1+ 51.Kh3 Qh1+ 52.Kg3 Qg1+ 0:01 1/6 0.14 74333 46.Qe8+ Kg5 47.h4+ Kf5 48.Qf7+ Ke4 49.e6 Qg1+ 50.Kh3 Qh1+ 51.Kg4 Qd1+ 52.Kg5 Qc1+ 53.Kg6 0:02 1/7 0.15 165279 46.Qe8+ Kg5 47.h4+ Kf5 48.Qh5+ Ke4 49.Qe2+ Kd4 50.e6 Qa3+ 51.Kg4 Qe7 52.Qb2+ Ke4 0:04 2/8 0.20 368515 46.Qe8+ Kg5 47.h4+ Kf5 48.Qf7+ Ke4 49.e6 Qg1+ 50.Kh3 Qh1+ 51.Kg4 Qd1+ 52.Kg5 Qc1+ 53.Kg6 Qg1+ 54.Kh5 b4 0:15 3/9 0.54 1240443 46.Qe8+ Kg5 47.h4+ Kf5 48.Qf7+ Ke4 49.e6 Qg1+ 50.Kh3 Qh1+ 51.Kg4 Qd1+ 52.Kg5 Qg1+ 53.Kh6 Qe3+ 54.Kh5 Qe2+ 55.Kg5 Qg2+ 56.Kf6 0:40 4/10 0.54 3323922 46.Qe8+ Kg5 47.h4+ Kf5 48.Qf7+ Ke4 49.e6 Qg1+ 50.Kh3 Qh1+ 51.Kg4 Qd1+ 52.Kg5 Qg1+ 53.Kh6 Qe3+ 54.Kh7 Ke5 55.e7 Qe4+ 56.Kg7 2:42 5/11 1.02 13526236 46.Qe8+ Kg5 47.h4+ Kh6 48.Qxc6+ Kg7 49.Qf6+ Kh7 50.Qf7+ Kh6 51.Qe6+ Kg7 52.Qg4+ Kh7 53.Qf5+ Kg7 54.Qd7+ Kh6 55.Qd6+ Kh5 56.e6 Qe1+ 57.Kf3 Kxh4 58.Qxd5 jm
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