Search found 433 matches

by Aleks Peshkov
Thu Aug 09, 2007 2:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Why material imbalance tables are needed
Replies: 17
Views: 10591

Implementation is unimportant

I think the main problem is how to collect material evaluation chess knowledge. And how to make sure that this data is better then random numbers. The task is similar to Piece-Square-Tables: the function is very easy to evaluate, it is obviously better then nothing, but exact values are mainly a pur...
by Aleks Peshkov
Wed Aug 08, 2007 1:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: More uses for magics?
Replies: 14
Views: 7774

Re: Generalized bitboard pawn moves

Actually i am attired by the approach to flip sides at each move - and to therefor to have only white moves with only black capture targets ;-) Oops, rotated bitboards reincarnation. 8-) C++ templates can help to avoid source code duplication in cases: 1) white/black pieces moves; 2) not in check/q...
by Aleks Peshkov
Tue Aug 07, 2007 1:34 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: what is the rating advantage of hash in fixed depth search
Replies: 4
Views: 2248

Re: what is the rating advantage of hash in fixed depth sear

Instability is a difference between hashed result and research of the same node again is fundamental because of random difference in move ordering (killer/history tables moment states are "random" factors) between two separate searches of a single position at different time. Different move ordering ...
by Aleks Peshkov
Mon Aug 06, 2007 9:06 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: what is the rating advantage of hash in fixed depth search
Replies: 4
Views: 2248

Re: what is the rating advantage of hash in fixed depth sear

Earlier or later fixed depth search will reach horizon. There is almost no difference (except random factor of transposition table instability), if your do not consider time.
by Aleks Peshkov
Tue Jul 17, 2007 11:42 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: standard chess piece set
Replies: 7
Views: 3542

Re: standard chess piece set

The reason of Elo drop if I ignore second queen moves by opponent, it will lead to illegal moves and immediate game lose unless this queen is captured soon.
by Aleks Peshkov
Tue Jul 17, 2007 11:09 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: standard chess piece set
Replies: 7
Views: 3542

standard chess piece set

I am playing with a board representation that can be greatly simplified in a case of max 1 queen, 2 rooks... per side. More general material state will need extra variables instead of immediate constants. I want to test simple version before implement "full chess rules". Rybka's beta did not know un...
by Aleks Peshkov
Tue Jul 03, 2007 7:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Iterative DTS
Replies: 17
Views: 10663

Re: Iterative DTS

Jump table is generally slow, because it is not use modern processors' branch prediction heuristics.
by Aleks Peshkov
Mon Jul 02, 2007 5:56 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Iterative DTS
Replies: 17
Views: 10663

Re: Iterative DTS

I do not know what is DTS, but

Code: Select all

      current->phase=PHASE_TREE_START_B;
      continue;
is slow comparing to simple unconditional

Code: Select all

goto PHASE_TREE_START_B;
by Aleks Peshkov
Mon Jun 25, 2007 9:17 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Article on proposed heuristic for computer chess program
Replies: 11
Views: 6228

Re: Article on proposed heuristic for computer chess program

Well, term "pressure" I have taken from the topic article just to point that it is not equal to mobility. I think it is good to bonus any single attacking/defending for any known weak spot, even if the immediate move here is tactically losing. I think it is useful to bonus any general progress in ta...