Author: Laszlo Gaspar
Date: 07:42:14 01/06/06
Go up one level in this thread
On January 06, 2006 at 10:21:21, Uri Blass wrote: >On January 06, 2006 at 07:19:47, Joseph Ciarrochi wrote: > >>If you run tournments limiting ply to 3, Rybka absolutely kills fruit and >>fritz9. >>Rybka sure forms a good first impression.:) >> >> >> >> >> >> 1 2 3 >>1 Rybka 1.0 Beta 32-bit **** 94.0 - 7.0 94.5 - 6.5 >>189.5/203 >>2 Fritz 9 7.0 - 94.0 *** 58.5 - 42.5 >>77.0/220 >>3 Fruit 2.2 6.5 - 94.5 42.5 - 58.5 ** >>55.5/221 >> >> >> >>These numbers seem so imbalanced. I wonder if there is not some sort of bug in >>the fritz gui or something. >> >>best >>Joseph > >Your title is misleading so I changed it in my reply. >My opinion is that Rybka searches x+2 plies when it claims to search x plies. > >From my experience it can see at fixed depth of 1 ply things that other programs >see at fixed depth of 3 plies > >Here is an example > >[D]3k2r1/ppb5/3p4/r2N1p2/8/8/1P6/1K2RB1R b - - 0 1 >[D]3k2r1/pp1b4/3p4/r2N1p2/8/8/1P6/1K2RB1R b - - 0 1 > >Rybka does not capture the knight at depth 1 in the first case but capture the >knight ar depth 1 in the second case. > >Can Vasik explain why? > >evaluation? >I do not believe it. > >It must be search and rybka search after Rxd5 Bc4 black move and see that in the >first case no move save black from a loss of full rook when in the second case >it searches Rxd5 Bc4 Bc6 > >Uri Hi all, It's clearly seen that Rybka uses some form of selective search different from others' in the quescence search which is not a full width search, therefore is not counted in nps. This explains the low nps, Rybka does extra work in the QS which pays off. Obvious, that a usual 1 ply search cannot be such better even with a superb evaluation but a Rybka-type can be. Regards, László
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