Author: Uri Blass
Date: 07:43:32 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 I can add that all my tactical tests suggest that rybka see at depth 1 everything that other programs see at depth 3 including pins that happen only in the third ply. [D]3k2r1/ppb5/3p4/r2Np3/6P1/7R/1P2B3/2K4R b - - 0 1 Rybka likes Rxd5 and when the king is at b1 it avoids Rxd5 at depth 1. [D]7k/7P/4b1pK/5P2/pp6/8/8/8 w - - 0 1 Rybka takes the pawn and not the bishop at depth 1. Anpther example [D]k7/p1p1p3/1P6/b2P4/2P1P3/P7/1P6/1K6 w - - 0 1 Rybka needs depth 2 to find b4 when other programs need depth 4. I am sorry but depth x of rybka is misleading and it is better if vasik changes it to depth x+2 because the program really searches depth x+2 bsed on all my tests. Uri
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