Author: Ryan B.
Date: 13:04:17 01/29/06
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On January 29, 2006 at 07:12:15, enrico carrisco wrote: >On January 29, 2006 at 06:46:35, Ryan B. wrote: > >>On January 29, 2006 at 06:23:45, Jouni Uski wrote: >> >>>It's stunnigly big if we compare to other top engines: >>> >>>Toga 163 840 ! >>>Fritz 446 464 >>>Fruit 704 512 >>>Shredder 802 816 >>> >>>Can any programmer give a quess, what's the reason? Is it simply a lot of >>>knowledge? Or bad compiler? Totally different approach? >>> >>>Jouni >> >>The size is mostly a bunch of tables. Disassembled the code is about 6.4MB and >>decompiled and cleaned up a little it is still about 3MB. It is defiantly not >>chess knowledge. The eval is actually very fruit like. >> >>Ryan > >Hello Ryan. > >Did you notice any "tactical-theme" based hidden assymetrical search? It seems >a "fruit-like" 10-ply primary search could work with an added N ply of a very >fast search with captures and checks, etc. > >That would explain its "long think" on positions when there are lots of >captures. The very fast final search does not do a full eval but only does some >table look-ups based on pre-initialized data at 10-ply, for example. > >The full PV or the garbage (positionally) at the end of the line can't be shown >or the cat's out of the bag. This extra layer of search, however, does give it >a very good tactical ability. > >Reminds me of Deep Thought -- using the hardware for the last N plies. This >type of tactical search works real efficiently to see danger from your opponent >but less efficient in finding chances for itself (ex: Genius.) Tactically it >makes it very strong but not so efficient in king attacks compared to Fritz or >Hiarcs. Hence, on test positions it does slightly worse (just like Fruit.) > >Regards, > >-elc. It does look like a "hidden" search using the tables but I think the captures issues is different. Otherwise I think you are right about how Rybka's search works. Ryan
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