Search found 2903 matches

by Evert
Sun Feb 06, 2011 3:00 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

In other news, the version of Sjaak I sent to you earlier may be fine. I still haven't found the problem, but testing older revisions shows that the problems I have now have been introduced either shortly before or after the revision I sent you. Ok, and now I have finally found the problem: I made ...
by Evert
Sat Feb 05, 2011 11:57 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

On-the-fly building of end-game tables would be a good solution for determining mating potential of single pieces or simple piece combinations. Mating potential or winning advantage is difficult to derive from piece values. E.g. KNNK is draw with a very large advantage, (despite the fact that there...
by Evert
Sat Feb 05, 2011 10:14 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Finding the move
Replies: 14
Views: 2027

Re: Finding the move

I find it difficult to see what would cause this switch since the knight appears well posted on the central square, PST etc would make it difficult to move Ng6. Any ideas? How do these engines decide to switch from Bd7 to Ng6? Well, I have no idea why it does it, but Jazz does switch to Ng6 at 11 p...
by Evert
Sat Feb 05, 2011 8:33 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

It looks like we need opening positions badly. I have seen games being replayed until one of the engines make a slightly different move. My random numbers are generated with a different seed each time so that helps I guess. Problem is, I don't think we have a good sense of what makes for a good bal...
by Evert
Sat Feb 05, 2011 4:47 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

My only experience is with determining piece values (which I shared with you). Another tuning method I use is watching games, to spot things that seem obviosly wrong froma strategicpoint of view. (Like advancing passers too early, so they are lost.) I currently use h:100/C:300/L:310/K:475/G:725/W:8...
by Evert
Sat Feb 05, 2011 4:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

Also mobility may be important but probably too costly in mailbox board representation. Is it? I don't actually know, but it is used there, right? I think mobility may well be the easiest way to make a general engine, if done properly. The reason I think so is that OliThink is reasonably strong usi...
by Evert
Sat Feb 05, 2011 4:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

In other news, the version of Sjaak I sent to you earlier may be fine. I still haven't found the problem, but testing older revisions shows that the problems I have now have been introduced either shortly before or after the revision I sent you. I'll test that exact version and let you know. Prelim...
by Evert
Sat Feb 05, 2011 2:12 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

I think it would be justified to grant a special status to Pawns / Hoplites. (you know, 'soul of the game' and that). They are relly not normal pieces: 1) Their moves are irreversible 2) They are tactically inept 3) They promote to a piece strong enough to decide the game Most Chess variants do hav...
by Evert
Sat Feb 05, 2011 1:10 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

Spartacus also does not have any real King Safety yet. (In normal Chess it just tries to freeze the King on c1/g1, and the a/b/c or f/g/h Pawns on 2nd rank, through the piece-square tables). I use a modified version of the king safety algorithm described by Ed Schroeder. The main difference is I us...
by Evert
Sat Feb 05, 2011 12:57 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Getting ready for Thermopylae
Replies: 56
Views: 4788

Re: Getting ready for Thermopylae

Another difficulty I encountered is passed pawn & hoplite eval. The hoplite movement make things difficult. They move diagonally and you can't tell if a pawn is passed or not at least not that easily. Same goes also for passed hoplites. What I did is to just stick with absolute passed pawns on the ...