Search found 230 matches

by Pradu
Sat Jul 24, 2010 8:49 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: ChessLisp for everyone!
Replies: 19
Views: 3691

Re: ChessLisp for everyone!

Lisp is a great language but many implementations seem to have to trade off performance for functionality. Have you looked into Lisp dialects intended fast execution such as PreScheme?
by Pradu
Tue Apr 20, 2010 11:41 am
Forum: Computer Chess Club: General Topics
Topic: Dirty 14M-22 Released
Replies: 4
Views: 1319

Re: Dirty 14M-22 Released

Aser Huerga wrote:Hello Andrés,

what can you say about these tweaks you are testing? I plan to join Dirty to a tournament about spanish and latin engines in the near future, and I ask myself if there will be another Dirty version soon...

Regards.
Perhaps there will be one this weekend.
by Pradu
Thu Feb 11, 2010 2:08 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Question about node type in a PVS search
Replies: 3
Views: 1067

Re: Question about node type in a PVS search

mathmoi wrote:Hi,

I have a simple question. In a PVS search, in a PV node, if one of the children after the first fail high, I have to search it again with a non-null window. When I do this research, is this node a PV node?

Thanks,

MP
Yes. http://chessprogramming.wikispaces.com/Node+Types
by Pradu
Wed Dec 30, 2009 9:57 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Gaviota TBs, compression schemes
Replies: 30
Views: 5041

Re: Gaviota TBs, compression schemes

michiguel wrote:I am done writing the compressor for the endgame tablebases (tbcp)...
Are there any good resources describing LZMA? I realize that there's already some C code, but I don't think it will be that useful to learn the algorithm.
by Pradu
Sat Nov 21, 2009 5:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Winning percentage and centipawns
Replies: 10
Views: 3210

Re: Winning percentage and centipawns

This is similar to the results I obtained for material-imbalance self-play of Fairy-Max, and an experiment I read about with pawn-odds games for Rybka 1-min games. The latter found ~74% score advantage, while I found 68%. But In my measurements I averaged out the white advantage, while the Rybka re...
by Pradu
Sat Nov 21, 2009 4:39 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Winning percentage and centipawns
Replies: 10
Views: 3210

Re: Winning percentage and centipawns

http://chessprogramming.wikispaces.com/Pawn+Advantage%2C+Win+Percentage%2C+and+ELO That is an interesting graph. Odd that they show a model fitted for K=4 when the tails would be better represented with K=5. Is there some empirical reason not to vary K for a best fit solution? Regards, Martin Brown...
by Pradu
Thu Aug 27, 2009 7:51 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Linear vs. Nonlinear Evalulation
Replies: 13
Views: 4142

Re: Linear vs. Nonlinear Evalulation

Gerd Isenberg wrote:I have a question about the definition of linear versus nonlinear evaluation.
Is there any advantage to having a linear vs non-linear evaluation function? Would it make analyzing an evaluation function significantly easier if it was linear?
by Pradu
Thu Aug 27, 2009 7:31 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Linear vs. Nonlinear Evalulation
Replies: 13
Views: 4142

Re: Linear vs. Nonlinear Evalulation

PSTs would be nonlinear because PST[sq1+sq2] != PST[sq1] + PST[sq2] I guess PSTs are linear if you define your function differently (with 64 discrete inputs instead of one). For example take a knight position PST: PSTeval(ispieceonsq1 , ispieceonsq2, ispieceonsq3... ispieceonsq64) where ispieceonsq...
by Pradu
Thu Aug 27, 2009 7:04 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Linear vs. Nonlinear Evalulation
Replies: 13
Views: 4142

Re: Linear vs. Nonlinear Evalulation

I have a question about the definition of linear versus nonlinear evaluation. Linear eval is the dot-product of features and weights. Assuming a passed pawn piece-square table contains for instance the square (x*x) of baserank distance (x), is this still linear evaluation? Is nonlinear eval necessa...
by Pradu
Sun Aug 16, 2009 9:14 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Questions on volatile keyword and memory barriers
Replies: 35
Views: 4739

Questions on volatile keyword and memory barriers

I've recently learnt about memory barriers and am rather confused about what they are meant to do and how they are different from what the volatile keyword does. From my understanding: - A read barrier makes sure all reads operations after the barrier happen after read operations before the barrier....