Search found 16848 matches

by bob
Mon Jul 02, 2007 7:44 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 'undercut' hash-replacement scheme
Replies: 9
Views: 5818

Re: 'undercut' hash-replacement scheme

My only comment is this. Given the choice of replacing one of N entries, I can't imagine a circumstance where I would choose to replace with a deeper draft as opposed to replacing one with a shallower draft. The two-tiered table (Belle approach) addresses two main issues. (1) keep the deep draft ent...
by bob
Mon Jul 02, 2007 6:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 'undercut' hash-replacement scheme
Replies: 9
Views: 5818

Re: 'undercut' hash-replacement scheme

The question has to be "why" however. Because of this: http://home.hccnet.nl/h.g.muller/hashnew.jpg The graph shows that shallowest-of-4 replacement, which is effectively an implementation of the Bell scheme with a depth-preferred table 3 times the size of the always-replace table, performs signifi...
by bob
Mon Jul 02, 2007 6:17 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Iterative DTS
Replies: 17
Views: 10318

Re: Iterative DTS

I rewrote the main parts of LOOPs recursive search engine. Now LOOP is searching iterative in order to implement DTS. But the first tests have shown that the searchspeed decreased about 10% compared to the recursive version. Both search engines are producing identical searchtrees, therefore I dont ...
by bob
Sun Jul 01, 2007 8:50 pm
Forum: Computer Chess Club: General Topics
Topic: Bob Hyatt Crafty 21.5 and 21.6
Replies: 10
Views: 4790

Re: Bob Hyatt Crafty 21.5 and 21.6

Hello Will one or both in the title above be sent to Chessbase for them to make their versions? Please! Also could you ask the nice Chessbase people if they could release 64 bit versions? Thanks in advance :!: Chris. we have been doing some final tuning for a couple of months, but recently I have s...
by bob
Fri Jun 29, 2007 5:47 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Will single processor software run on mp?
Replies: 2
Views: 1836

Re: Will single processor software run on mp?

Take a look at here http://www.dailytech.com/article.aspx?newsid=7839 Best regards, Alvaro Cardoso This is not that new. But it just doesn't work for chess. Ken Kennedy at Rice worked on this type of problem for _years_. and they produced good results for some simple algorithms with huge computatio...
by bob
Fri Jun 29, 2007 2:06 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: 'undercut' hash-replacement scheme
Replies: 9
Views: 5818

Re: 'undercut' hash-replacement scheme

The question has to be "why" however. One ply represents a significant amount of work, yet it gets tossed out more frequently. That seems pretty ad hoc. I don't see how it is going to beat the old Belle (2-table) approach, which is even better about "always storing" an entry to make sure that local ...
by bob
Fri Jun 29, 2007 1:19 am
Forum: Computer Chess Club: General Topics
Topic: What is faster for endgame tables
Replies: 35
Views: 14547

Re: What is faster for endgame tables

Hi ! Here's the thing. I did the original testing for compressed tablebases, and tried all sorts of blocksizes to see which offered the best tradeoff with respect to CPU operations vs disk drive transfers. We are not using 4K blocksizes. I honestly don't remember whether we settled on 8K or 16K for...
by bob
Thu Jun 28, 2007 12:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Does your engine offer and accept draws?
Replies: 9
Views: 4238

Re: Does your engine offer and accept draws?

Hi Bob Thanks very much for the suggestions. Actually I haven't got around to thinking about offering draws in any detail, as I feel its likely to be needed less often. However, your draw-counter looks like a very sensible idea. I'll take a peek at Crafty's code, thanks. And of course the engine mu...
by bob
Thu Jun 28, 2007 12:23 am
Forum: Computer Chess Club: General Topics
Topic: What is faster for endgame tables
Replies: 35
Views: 14547

Re: What is faster for endgame tables

Hi Pax, I am using a 8GB usb Memory stick (flash, no minidrive). Acess time very fast (0,7) from transcend - jetflash 160. All tbs 1-5 men fit on it. The acess is very good. I can see no more low nps with Shredder 9 e.g. I agree ! Until now there is no HDD and/or technology which is better (faster)...
by bob
Wed Jun 27, 2007 1:03 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Does your engine offer and accept draws?
Replies: 9
Views: 4238

Re: Does your engine offer and accept draws?

I am currently adding code to ermintrude's ICC interface to allow her to offer and accept draws from opponents. This is partly motivated by consideration for human players who reach an obviously drawn position but are currently made to force a repetition in order to claim the draw, but mostly from ...