Search found 603 matches

by zamar
Tue Mar 31, 2015 10:36 am
Forum: Computer Chess Club: General Topics
Topic: Stockfish "6.1 SMP" release?
Replies: 18
Views: 5583

Re: Stockfish "6.1 SMP" release?

Isn't +70 ELO for high end computers worth of official compile now!? There has been commercial releases for 10-20 ELO or even less :wink: . To guarantee the quality of a release, we'll release at maximum twice a year. People who want to have the latest and greatest and can always download and use t...
by zamar
Tue Mar 31, 2015 10:29 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: txt: automated chess engine tuning
Replies: 113
Views: 30473

Re: txt: automated chess engine tuning

Joerg Oster wrote:Really odd!
All values are now at their maximum or minimum. :?:
That shouldn't happen... Sounds like a bug in tuner implementation...
by zamar
Mon Mar 30, 2015 2:23 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: txt: automated chess engine tuning
Replies: 113
Views: 30473

Re: txt: automated chess engine tuning

2) I selected quiet positions from CCRL game database. My definition for quiet was: eval = qsearch(), also excluded positions in the very late endgame. I also made another attempt where I modified qsearch() to actually save fens of all quiet positions it encountered during the search with certain l...
by zamar
Mon Mar 30, 2015 12:09 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: txt: automated chess engine tuning
Replies: 113
Views: 30473

Re: txt: automated chess engine tuning

Years ago, I tried to do (almost) exactly what you describe there with Stockfish. Even with a simple hill climb algorithm, the algorithm converged extremely fast into certain values. Unfortunately the results were always a disaster in practical tests... I think Komodo team has reported similar resu...
by zamar
Mon Mar 30, 2015 10:11 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: txt: automated chess engine tuning
Replies: 113
Views: 30473

Re: txt: automated chess engine tuning

Hi, all! I wrote a small framework to do automated chess tuning based on Texel's Tuning method ( https://chessprogramming.wikispaces.com/Texel%27s+Tuning+Method ). You can find the source code and instructions how to use it here https://bitbucket.org/brtzsnr/txt . I'm still experimenting with it, s...
by zamar
Wed Feb 18, 2015 8:36 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Explanation for non-expert?
Replies: 43
Views: 8049

Re: Explanation for non-expert?

I'm no where near an expert on parallel alpha-beta, but it seems to me that people in this thread are reinventing optimal scheduling of jobs related to potential split points. AFAICS, this is mostly solved in the literature by randomized work-stealing such as pioneered by Cilk-chess and currently a...
by zamar
Wed Feb 18, 2015 7:20 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Explanation for non-expert?
Replies: 43
Views: 8049

Re: Explanation for non-expert?

For a given move at a potential split point it then computes the expected "efficiency", defined as p1 * p2 * ... * pN * (1 - overhead), where p1, ..., pN are the estimated probabilities that the moves for the current and all "parent" split points need to be searched. Finally it picks the move with ...
by zamar
Wed Feb 18, 2015 8:10 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Explanation for non-expert?
Replies: 43
Views: 8049

Re: Explanation for non-expert?

Hi Bob, #1 is not quite so simple. If you split below a split point, you still incur about the same amount of overhead. This is a sort of similarity one might find with speculative execution in a modern CPU. Remember that the only overhead you incur is the overhead searched by this new thread, if th...
by zamar
Tue Feb 17, 2015 10:47 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Explanation for non-expert?
Replies: 43
Views: 8049

Re: Explanation for non-expert?

There is no magic here. This stuff has been known since '80s. Two key factors to consider when/how to split: 1) Each time you split there is a price to pay. 2 threads working on the same split point, one of them produces cut-off, the work of the other thread is wasted. We could say that you are gett...
by zamar
Sun Feb 08, 2015 6:43 am
Forum: Computer Chess Club: General Topics
Topic: Binders
Replies: 22
Views: 3893

Re: Binders

A very interesting proposition. I'll do a couple of tests, to see if this idea yields anything in practice. I feel this is definitely worth of try. Even a patzer like me knows that a knight on D5 supported by E4 and C4 can be a real nuisance... A naive implementation just passed fishtest: Give bonu...