Search found 5 matches

by Alexander Zacharias
Fri Apr 18, 2014 2:59 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: To be, or not to be checkmated
Replies: 19
Views: 4365

Re: To be, or not to be checkmated

I guess this is actually a pretty general pattern, not just applicable to pending mates: the PV move from the previous iteration drops tremendously in score, and now you find at that same iteration some other moves that make the score drop less, namely by approximately the value of the piece that y...
by Alexander Zacharias
Thu Aug 15, 2013 4:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Threat detection near the leaves
Replies: 1
Views: 648

Re: Threat detection near the leaves

I'd say it's a trade off between speed and accuracy, as nearly always. So if you believe the accuracy loss of a certain algorithm to outweight the speed gain in terms of playing strength / elo the best thing you could do in my opinion (besides proving it analytically ;-)) is verifying it: measure th...
by Alexander Zacharias
Tue Apr 09, 2013 10:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New 6-piece tablebases
Replies: 194
Views: 104198

Re: New 6-piece tablebases

What do you mean by performance data??? The code is very quick, and works well. I originally thought of performance as game-playing-performance, measured in ELO. Though it would be interesting to know how fast the access is if the needed part of the tablebase is already in RAM. Don't expect a stock...
by Alexander Zacharias
Tue Apr 09, 2013 6:10 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New 6-piece tablebases
Replies: 194
Views: 104198

Re: New 6-piece tablebases

I'm quite enthusiastic about this, though I don't have the necessary RAM at hand yet.
Do you have performance data? What playing strength did your program gain by using the 6-man tables? Can you estimate the gain for Stockfish?
by Alexander Zacharias
Thu Jun 07, 2012 1:05 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: MP Implementation: One Method or Varied?
Replies: 25
Views: 4770

Re: MP Implementation: One Method or Varied?

This is the basic idea of "optimistic pondering" (Himstedt, ICGAJ 2005), implemented in "GridChess" (WCCC 2007) and "Cluster Toga" (WCCC 2008). I think it has some potential even on single cpu systems if the number of cores per cpu continues to grow, as YBWC/DTS etc. search efficiency degrades with ...