Search found 18115 matches

by hgm
Sat Feb 08, 2020 9:59 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Endgame woes
Replies: 12
Views: 700

Re: Endgame woes

Well, if it would take 100 ply after the conversion you would not find it anyway, even if you did search to full depth. But I guess it would indeed be saver to reduce the depth (or the depth over a certain minimum number of ply) by a factor than to put a hard limit on it. Then you won't spoil the pr...
by hgm
Sat Feb 08, 2020 7:52 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Endgame woes
Replies: 12
Views: 700

Re: Endgame woes

@hgm, when you write 'naive eval' I assume you mean the material + positional eval, and that's what gets adjusted? Indeed, that's the eval you would normally use, and says +3.25 when you are in KBK. Note that you can cut off some search work in end-games that in general are draws by reducing the se...
by hgm
Fri Feb 07, 2020 6:25 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Endgame woes
Replies: 12
Views: 700

Re: Endgame woes

I always use a method I learned from Fruit: multiply the naive eval by a factor < 1 when the material combination is recognized as drawis. There are several classes of drawishness: without Pawns and not more than a minor ahead is divided by 8, and end-games that can convert to it by sacrificing away...
by hgm
Fri Feb 07, 2020 2:09 pm
Forum: Computer Chess Club: General Topics
Topic: Arena 3.9 beta for Linux
Replies: 34
Views: 3432

Re: Arena 3.9 beta for Linux

[moderation] I think we should be pleased that there are some programmers who want to work for free and share the fruits of their labor with us. If you don't like Arena or the policy of its creator, just don't use it. Plenty of alternatives, some of them free as well. Insulting the whole population...
by hgm
Fri Feb 07, 2020 2:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Engines playing Musketeer Chess, good price
Replies: 111
Views: 7476

Re: Engines playing Musketeer Chess, good price

Oops, this is more than just graphics! Seems I was a bit over-enthousiastic when removing gateable pieces after capture of the piece in front of them. I uploaded the fixed version now.
by hgm
Thu Feb 06, 2020 7:16 pm
Forum: Computer Chess Club: General Topics
Topic: Perfect play
Replies: 13
Views: 544

Re: Perfect play

It would be above 50%, but I would be surprised if it was above 50.5%. The number of poor moves is usually a lot larger than the number of good moves, so if it not close to the brink of losing (so that most poor moves will be rejected), it will deteriorate its position pretty fast. The draw margin i...
by hgm
Thu Feb 06, 2020 6:23 pm
Forum: Computer Chess Club: General Topics
Topic: Perfect play
Replies: 13
Views: 544

Re: Perfect play

I don't think a pure 32-men EGT would achieve better than 50%. It would recognize that the initial position is a draw, and would start randomly playing moves that preserve that draw. Which almost always will worsen its position. This will continue until it is at the brink of being lost. Then it will...
by hgm
Wed Feb 05, 2020 11:24 am
Forum: Computer Chess Club: General Topics
Topic: Could we use partial scoring for draws to improve evaluation of engine vs engine matches and tournaments?
Replies: 35
Views: 742

Re: Could we use partial scoring for draws to improve evaluation of engine vs engine matches and tournaments?

One should never award a result on the basis of the evaluation. That would just encourage engines to lie about their evaluation.
by hgm
Tue Feb 04, 2020 7:06 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Dense board representation as hash code
Replies: 8
Views: 901

Re: Dense board representation as hash code

One more thought: a radix-49 representation of the pawn structure takes 2log 49 = 5.6 bits/pawn, i.e. 90 bits for 16 pawns. This is very inefficient, because (as remarked) it treats all pawns as distinguishable. Uri Blass once proposed a 64-bit representation, consisting of a 48 bits 'pawn-occupancy...
by hgm
Mon Feb 03, 2020 8:20 pm
Forum: Computer Chess Club: General Topics
Topic: Classes of chess pieces for chess variants
Replies: 67
Views: 4324

Re: Classes of chess pieces for chess variants

Unfortunately new variants can only be added to the ICS code in a very cumbersome way. Even when they use a normal rectangular board. It would be possible for me to set up a turn-based server similar to http://hgm.nubati.net/variants/elven/ for a 12x12 board, but because of the unusual board topolog...