Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Quick question on Killer heuristic

Author: Dan Newman

Date: 11:31:19 05/03/00

Go up one level in this thread


On May 02, 2000 at 21:29:46, Robert Hyatt wrote:

>On May 02, 2000 at 20:35:09, William Bryant wrote:
>
>>In my program my killer table is simply an array of [ply][2] with two killers
>>allowed per ply.  When updating the killer table, I replace the first killer
>>with the new one (assuming it is not the same move), and move the old first
>>killer to the second killer position, dropping what ever move is in the second
>>killer position.
>>
>>In the introductory paragraphs of Ernst's book, he describes using counters
>>to order the killer moves (page 23)
>>"The killer moves carry "hit" counters with them which specify their priorities
>>for sorting and replacement."
>>
>>This would, of course, require a larger table, and more time spent updating
>>and sorting the killer table.
>>
>>Is this more efficient or effective than a standard replace table?  Other
>>thoughts or comments about organizing the killer moves?
>>
>>Thanks.
>>
>>William
>>wbryant@ix.netcom.com
>
>
>I use counters...  I think this is the right way to do this...

Bob,

I just looked at Crafty v17.10 (to see if and where you zero the counters)
and didn't see them.  I suspect you got rid of the counters when you went
SMP (otherwise you'd have to do some locking to keep the counters and moves
coherent, I suppose).  [I've been zeroing the counters in my program in the
wrong spot I think...]

-Dan.



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.