Search found 17973 matches

by hgm
Tue Apr 03, 2007 2:53 pm
Forum: Computer Chess Club: General Topics
Topic: 2007 World Computer Quick Chess Championships
Replies: 29
Views: 15971

Re: 2007 World Computer Quick Chess Championships

Are you an American citizen, then? If not, tough luck, because they don't want you.

But this is an April-fool's-day joke, isn't it?
by hgm
Tue Apr 03, 2007 8:46 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

Even if you take an infinite number of positions it would still be meaningless if you did not measure tactical strength. Because you would select the move ordering systematically to reduce more moves by LMR, by putting poor, but non-reducible moves (like bad captures) in front, just to put interesti...
by hgm
Mon Apr 02, 2007 9:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

If I unerstand Tord correctly, the important point is that LMR is not a technique that preserves the quality of the search, while other techniques for move ordering (and even R=2 null-move pruning to a large extent) are guaranteed to find the same move and score. So with LMR switched on, you can min...
by hgm
Mon Apr 02, 2007 4:59 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

You can't do it all in parallel. You have to use some sort of "tree" to reduce it down to a single answer. Which is a tree of depth 6 for 64 squares... Each square could find its own answer easily, but then they have to "get together" and figure out which is the "best answer" and that adds sequenti...
by hgm
Mon Apr 02, 2007 4:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

bob wrote:I think it is sub-optimal no matter what. :)
Yes, but that what does it prove? Seems to me you are searching out-of-window already...
by hgm
Mon Apr 02, 2007 12:31 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

That would stretch the clock cycle time for _everything" since the clock cycle time has to be long enough for the most complex circuit in the thing to settle. MVV/LVA requires two minor cycles in a hardware implementation. First cycle is find the most valuable attacked piece (victim), second cycle ...
by hgm
Sun Apr 01, 2007 10:22 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

Then please cite a solution to the following problem. A hardware chess implementation is a finite state machine with a static cycle-time. So how are you going to implement a SEE that can do its thing in one cycle that is a constant-time thing? You can't. Either you stretch the cycle time out horren...
by hgm
Sat Mar 31, 2007 8:38 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

Can we stop with the blanket statements that are wrong? "no serious engine uses MVV/LVA". Let me name a few, from older to newer: (1) Belle (2) chiptest (3) deep thought (4) deep blue (5) dark thought (6) Hydra Well, so I left out the "anymore", obviously there has been a time when MVV/LVA was quit...
by hgm
Fri Mar 30, 2007 4:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

By the way, it is easy to prove that it is never worse to do an Equal-takes-Equal (let alone Lower-takes-Higher) capture of a victim with value VV>=s, than to capture something with a SEE=s. (Apart from accidental side effects, such as recapture by the intended victim of another capture, to which bo...
by hgm
Fri Mar 30, 2007 1:28 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE on non-capture moves in main search
Replies: 62
Views: 72210

Re: SEE on non-capture moves in main search

If the capturing piece is more valuable than the captured piece, I call the SEE, and search the move only if the SEE returns a non-negative value. OK, we do exactly the same upto the point where we have the SEE score. At that point, even if the SEE is positive, I replace the victim value by the SEE...