Author: Robert Hyatt
Date: 05:09:18 05/26/98
Go up one level in this thread
On May 26, 1998 at 00:08:53, James B. Shearer wrote: something definitely wrong there. looking at it right now... > I was playing a crafty clone on ICC a few days ago. It lost after >declining to take a pawn for no apparent reason. I was curious and >looked at the position after the game. Crafty 14.10 grabs the pawn. I >downloaded crafty 15.7 and it was reluctant to take the pawn. This is >not surprising because the score command gives a lower evaluation for >white (crafty) when the black pawn in question is removed. The pawn may >be weak but it certainly doesn't have negative value. Looks like a bug >of some sort to me. > This is the position. >Crafty v15.7 > >hash table memory = 12M bytes. >pawn hash table memory = 1.3M bytes. >pondering disabled. >book learning disabled >result learning disabled >position learning disabled >noise level set to 0. > >White(1): in all39 >White(1): setboard 3r3k/7p/p7/8/2Bp1P2/4r1P1/P6P/3R2K1 w - - 0 39 > > +---+---+---+---+---+---+---+---+ > 8 | | | | *R| | | | *K| > +---+---+---+---+---+---+---+---+ > 7 | | | | | | | | *P| > +---+---+---+---+---+---+---+---+ > 6 | *P| | | | | | | | > +---+---+---+---+---+---+---+---+ > 5 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 4 | | | B | *P| | P | | | > +---+---+---+---+---+---+---+---+ > 3 | | | | | *R| | P | | > +---+---+---+---+---+---+---+---+ > 2 | P | | | | | | | P | > +---+---+---+---+---+---+---+---+ > 1 | | | | R | | | K | | > +---+---+---+---+---+---+---+---+ > a b c d e f g h > >White(1): exit > >White(1): score >end-game phase > clearing hash tables >note: scores are for the white side >material evaluation................. -0.70 >development......................... 0.00 >pawn evaluation..................... 0.15 >passed pawn evaluation.............. -0.09 >passed pawn race evaluation......... 0.00 >interactive piece evaluation........ 0.46 >total evaluation.................... -0.18 > > Now remove the black a pawn and white's score goes down. > >White(1): in all39a >White(1): setboard 3r3k/7p/8/8/2Bp1P2/4r1P1/P6P/3R2K1 w - - 0 39 > > +---+---+---+---+---+---+---+---+ > 8 | | | | *R| | | | *K| > +---+---+---+---+---+---+---+---+ > 7 | | | | | | | | *P| > +---+---+---+---+---+---+---+---+ > 6 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 5 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 4 | | | B | *P| | P | | | > +---+---+---+---+---+---+---+---+ > 3 | | | | | *R| | P | | > +---+---+---+---+---+---+---+---+ > 2 | P | | | | | | | P | > +---+---+---+---+---+---+---+---+ > 1 | | | | R | | | K | | > +---+---+---+---+---+---+---+---+ > a b c d e f g h > >White(1): exit > >White(1): score >end-game phase >note: scores are for the white side >material evaluation................. 0.30 >development......................... 0.00 >pawn evaluation..................... 0.04 >passed pawn evaluation.............. -0.04 >passed pawn race evaluation......... 0.00 >interactive piece evaluation........ -0.60 >total evaluation.................... -0.30 > > Take the a pawn with the bishop and white's score goes down even >more. > >White(1): in all39b >White(1): setboard 3r3k/7p/B7/8/3p1P2/4r1P1/P6P/3R2K1 b - - 0 39 > > +---+---+---+---+---+---+---+---+ > 8 | | | | *R| | | | *K| > +---+---+---+---+---+---+---+---+ > 7 | | | | | | | | *P| > +---+---+---+---+---+---+---+---+ > 6 | B | | | | | | | | > +---+---+---+---+---+---+---+---+ > 5 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 4 | | | | *P| | P | | | > +---+---+---+---+---+---+---+---+ > 3 | | | | | *R| | P | | > +---+---+---+---+---+---+---+---+ > 2 | P | | | | | | | P | > +---+---+---+---+---+---+---+---+ > 1 | | | | R | | | K | | > +---+---+---+---+---+---+---+---+ > a b c d e f g h > >Black(1): exit > >Black(1): score >end-game phase > clearing hash tables >note: scores are for the white side >material evaluation................. 0.30 >development......................... 0.00 >pawn evaluation..................... 0.04 >passed pawn evaluation.............. -0.04 >passed pawn race evaluation......... 0.00 >interactive piece evaluation........ -0.82 >total evaluation.................... -0.52 >Black(1): quit >execution complete. > James B. Shearer
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