Author: scott farrell
Date: 17:38:05 08/24/02
Guys, Chompster is still going slow, but let's see if we can make it search smarter. I have the basics if SE going. If any of these, I do a serach extension single legal move, null move returns -INFINITY, isCheck, recapture The search extension is just doing search(-beta,-alpha,depth) instead of search(-beta,-alpha,depth-1) It seems to work OK. It solved one of my hard test positions in one ply less, but in about the same time, as it used many more nodes. My questions: - I cant work out the impact on the hash tables. For example, if when eventually return to the root of the tree, after a few SEs, and we store the value in the hashtable, what depth should we put on it? If we are searching all moves to 3 plies, and do 2 SE's during a particular branch search, should I not store it in the HT as depth=5 (and how do I work out depth=5?) - should there be a limit on how SE's you do. I know crafty does "no more than one ply of extensions are allowed at any one level in the tree". But it depends how how you look at "any one level in the tree", given SEs play around with the tree, as what this really means. - I found I just burned more nodes, and time, and generally about 5% worse on WAC for 1 and 2 seconds/position - I run all the calcs to determine if to do a SE (see above) before I iterate the moves and doMove (other than recapture which doesnt make sense without a move). I am unsure as to test things like isCheck before or after doMove. Scott sfarrell@icconsulting.com.au sfarrellc(ICC)
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