Search found 1191 matches

by mjlef
Wed May 16, 2007 1:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: a beat b,b beat c,c beat a question
Replies: 9
Views: 6086

Re: a beat b,b beat c,c beat a question

The solution is simple, never, ever play version X+2 of any program versus version X and cause this loop of confusion. If you do this it will just give you a headache! I know it has me!
by mjlef
Wed May 16, 2007 10:02 am
Forum: Computer Chess Club: Tournaments and Matches
Topic: Toga II 1.3 with HT=80
Replies: 2
Views: 1317

Re: Toga II 1.3 with HT=80

According to http://www.computerchess.org.uk/ccrl/404/ HT=80 is the best Toga version. I played 6*20 games against same engines to check. First default (HT=75): Toga II 1.3 - Rybka 2.3.1 32-bit 7.0 - 13.0 +5/-11/=4 35.00% Toga II 1.3 - Fritz 10 7.5 - 12.5 +5/-10/=5 37.50% Toga II 1.3 - Deep Sjeng 2...
by mjlef
Thu May 10, 2007 1:36 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: About pawn hash tables
Replies: 6
Views: 5785

Re: About pawn hash tables

In NOW, I also use both opening and endgame evaluations, but I do not interpolate for each individual feature. That would be a hundred or so multiplcations and divisions depending on the number of features measurd. I just sum all opening and endgame scores in two different variables and store them i...
by mjlef
Thu May 10, 2007 11:37 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Clone Solution: SOLOPO
Replies: 1
Views: 2573

Clone Solution: SOLOPO

Perhaps the best way to secure a program is to use an obscure programming language like SOLOPO: http://theshredder.com/archive/mir2.html In Russian, SOLOPO stands for Sotsialistichesky Ordena Lenina Organ Programmnogo Obespecheniya, rendered in English as "Socialist Software Tool decorated by Order ...
by mjlef
Mon May 07, 2007 6:23 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Advice on stabalizing the eval needed
Replies: 11
Views: 10507

Re: Advice on stabalizing the eval needed

In RomiChess the piece/square tables are created dynamically before each search. This can lead to some extreamly unbalanced evals leading to things like bad sacrifices and other pathalogical behaviors. So, what is best, limiting each square to a maximum or adding up all the squares and scaling them...
by mjlef
Fri Apr 27, 2007 9:34 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Speedup with bitboards on 64-bit CPUs
Replies: 49
Views: 34512

Re: Speedup with bitboards on 64-bit CPUs

I think it has been reported here Rybka, which Vasik says uses bitboards, runs about 60% faster on a 64 bit processor. I think the speed difference will depend greatly on what is being represented with 64 bit values. Lately, I have kept my mailbox move generation, but use some incrementally update b...
by mjlef
Mon Apr 16, 2007 12:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Material imbalance evaluation
Replies: 10
Views: 12734

Re: Material imbalance evaluation

Hi, I think everybody knows Kaufman's article on evaluating material, but just in case: http://mywebpages.comcast.net/danheisman/Articles/evaluation_of_material_imbalance.htm So far I haven't had any luck adding those corrections in Hamsters, but I would like to go deeper on the subject. Is there a...
by mjlef
Wed Apr 04, 2007 1:16 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Futility pruning question
Replies: 16
Views: 16763

Re: Futility pruning question

You should not futility prune if in check, the move gives check, or the move is likely to effect a score change big enough to raise the score above alpha--like making a passed pawn. If your margin of 200 covers this, then it should be good. It certainly does not cover things well enough in NOW. I ha...
by mjlef
Tue Apr 03, 2007 10:53 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: LearningLemming jumps off a cliff and dies
Replies: 15
Views: 18793

Re: LearningLemming jumps off a cliff and dies

That is good news, since the second time you write a program it always comes out better. You can restructure the data to betetr suit what you ended up doing. Ask Tord...he keeps starting from scratch and it gets better every time!