Search found 16819 matches

by bob
Fri May 04, 2007 8:22 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Programmer bug hunt challenge
Replies: 32
Views: 28709

Re: Programmer bug hunt challenge

Well, as the e.p. square here is only used to decide if the following move is legal, and not for determining if positions are different for hashing or applying the 3-rep rule, it is not a bug to consider that e.p. rights exist when no Pawn is present to enjoy these rights... Yes, precisely. Note it...
by bob
Fri May 04, 2007 8:20 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Programmer bug hunt challenge
Replies: 32
Views: 28709

Re: Programmer bug hunt challenge

Well, as the e.p. square here is only used to decide if the following move is legal, and not for determining if positions are different for hashing or applying the 3-rep rule, it is not a bug to consider that e.p. rights exist when no Pawn is present to enjoy these rights... It's maybe not a "bug",...
by bob
Fri May 04, 2007 8:19 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Programmer bug hunt challenge
Replies: 32
Views: 28709

Re: Programmer bug hunt challenge

I do not understand the bug There was no enpassent capture possible in the end of the first game so I do not see how clearing enpassent square between games could be relevant. There was no black pawn at b4 in the final position of the game. Uri some programs incorrectly (IMHO) set an EP target when...
by bob
Fri May 04, 2007 8:17 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting position from Jouni Uski
Replies: 27
Views: 22808

Re: Interesting position from Jouni Uski

I have tried again with the same commands posted above and obtained the same result you posted (i.e. correct mate found)... who knows what I did when I tried that for the first time! :shock: OK. To the best of my knowledge I haven't had an EP bug in many years. Except for the cases where a GUI fail...
by bob
Fri May 04, 2007 8:15 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: KQKB and KQKN heuristic for bitbases?!
Replies: 2
Views: 3419

Re: KQKB and KQKN heuristic for bitbases?!

For those kinds of endings, I don't think you even need 'em. KQKR is more difficult than either of those, and a simple "drive the king to the edge/corner and keep the kings close together is more than enough to force the win with kqkr. With kqkb or kqkn it is even easier...
by bob
Fri May 04, 2007 7:47 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Advice on stabalizing the eval needed
Replies: 11
Views: 11125

Re: Advice on stabalizing the eval needed

In RomiChess the piece/square tables are created dynamically before each search. This can lead to some extreamly unbalanced evals leading to things like bad sacrifices and other pathalogical behaviors. So, what is best, limiting each square to a maximum or adding up all the squares and scaling them...
by bob
Fri May 04, 2007 7:44 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting position from Jouni Uski
Replies: 27
Views: 22808

Re: Interesting position from Jouni Uski

you need to figure out why Crafty failed the test, when it works perfectly for any version I tried... There is definitely an interface or operator issue involved here. At the time I did a quick test with Crafty on Mac OS X (it was version 19.13 IIRC, downloaded with Fink), just open a terminal, run...
by bob
Fri May 04, 2007 3:11 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting position from Jouni Uski
Replies: 27
Views: 22808

Re: Interesting position from Jouni Uski

you need to figure out why Crafty failed the test, when it works perfectly for any version I tried... There is definitely an interface or operator issue involved here.
by bob
Fri May 04, 2007 3:09 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting position from Jouni Uski
Replies: 27
Views: 22808

Re: Interesting position from Jouni Uski

Crafty sees this just fine: White(1): move time surplus 0.00 time limit 22.50 (+0.00) (3:30) depth time score variation (1) 1 0.00 -2.24 1. Rxd4 1 0.00 Mate 1. dxe6# 1-> 0.00 Mate 1. dxe6# 2 0.00 Mate 1. dxe6# 2-> 0.00 Mate 1. dxe6# 3 0.00 Mate 1. dxe6# 3-> 0.00 Mate 1. d...
by bob
Tue May 01, 2007 9:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Checks and move ordering
Replies: 11
Views: 11231

Re: Checks and move ordering

I have been working on my move generator and now I know if a move gives check before I make it. Now I am wondering how I should use this information in move ordering, e.g. should a winning capture that gives check be tried ahead of winning captures that appear to gain more material, or should disco...