Author: Uri Blass
Date: 07:47:22 01/06/06
Go up one level in this thread
On January 06, 2006 at 10:42:14, Laszlo Gaspar wrote: >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 No It is not clear I can achieve the same effect by not counting nodes in the qsearch and writing depth x when the real depth is x+2 It is possible that rybka does nothing special except playing better when vasik tries to hide what it does by misleading information. Uri Uri
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