Search found 155 matches

by micron
Tue Feb 21, 2012 11:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Null Move Help
Replies: 28
Views: 3143

Re: Null Move Help

I'm getting a lot of draw results, even with the transposition table disabled. About 50% of the games end in a draw. I have repetition detection and I return a score of 0 when a repetition is encountered. Am I doing that right? Should I be returning a lower score when it sees a repetition, or skip ...
by micron
Sat Feb 18, 2012 2:13 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: On-line blitz tourney February
Replies: 5
Views: 820

Re: On-line blitz tourney February

Did you forget the -autoKibitz option?
by micron
Wed Feb 15, 2012 12:09 am
Forum: Computer Chess Club: General Topics
Topic: Do you like the XBoard home page?
Replies: 12
Views: 1571

Re: Do you like the XBoard home page?

The page fails to mention Mac OS X. This omission biases me against the page, so that I too can't vote.
by micron
Fri Feb 10, 2012 12:49 am
Forum: Computer Chess Club: General Topics
Topic: Prédateur 2.2.1 "Bugfix" released (now with PPC)
Replies: 17
Views: 1031

Re: Prédateur 2.2.1 "Bugfix" released (now with PP

There is still a time bug. $ cutechess-cli.sh tc=40/2 proto=uci -engine cmd=/chess_engines/Spandrel -engine cmd=/chess_engines/Predateur_Mac_Intel Started game 1 of 1 (Spandrel vs Predateur v2.2.1_Mac_Intel) ELO difference: inf Finished match Finished game 1 (Spandrel vs Predateur v2.2....
by micron
Thu Feb 09, 2012 11:12 pm
Forum: Computer Chess Club: General Topics
Topic: Prédateur 2.2.1 "Bugfix" released (now with PPC)
Replies: 17
Views: 1031

Re: Prédateur 2.2.1 "Bugfix" released (now with PP

- fixed the time bug - made all uci options lowercase (does CuteChess still protest?) CueChess no longer protests. There is still a time bug. $ cutechess-cli.sh tc=40/2 proto=uci -engine cmd=/chess_engines/Spandrel -engine cmd=/chess_engines/Predateur_Mac_Intel Started game 1 of 1 (Spandrel vs ...
by micron
Sun Feb 05, 2012 10:38 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Null Move Help
Replies: 28
Views: 3143

Re: Null Move Help

NMP, like most modifications to an engine, changes the search tree and so it is entirely normal to get a different score and PV. NMP should give you a big improvement in time-to-depth (or nodes at given depth). In my engine NMP reduces those metrics to a half at low depths and a quarter in deep sear...
by micron
Sat Feb 04, 2012 11:30 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Moving to Magic Bitboards... any advice?
Replies: 14
Views: 2909

Re: Moving to Magic Bitboards... any advice?

A minor point of terminology. There are no 'magic bitboards'. There are many methods to generate slider attacks with bitboards, some of which use 'magic' multiplication. As a precursor to magic slider attack generation, the classic 4-ray, loop-free, branch-free method has some advantages, including ...
by micron
Fri Feb 03, 2012 3:26 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: C# Performance
Replies: 121
Views: 14080

Re: C# Performance

r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1 has 193690690 leafnodes to depth 5, which took the program 78s, or 2488kns. I used the nprof profiler, here are the results: IsAttacked is an obvious candidate for optimisation [snip] After I've finished the evaluation function, I...
by micron
Mon Jan 30, 2012 9:25 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: A few general questions...
Replies: 26
Views: 4458

Re: A few general questions...

By the way, if alpha and beta are the same, it's logically inconsistent because if a score is returned that is equal to alpha AND beta then it has failed high AND it has failed low - which is illogical. And so it is strongly recommended to put this at the top of Search() and QSearch(): assert( ...
by micron
Sun Jan 29, 2012 9:11 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: A few general questions...
Replies: 26
Views: 4458

Re: A few general questions...

1. How can you get an exact score for each root move? (So you can sort them for the next iteration) The obvious way is to reset alpha beta to infinity window for each root move, however...this will slow down the search quite a bit... You might do that for preliminary ordering of the root moves, for...