Author: Vincent Diepeveen
Date: 05:59:10 06/04/02
Go up one level in this thread
On June 04, 2002 at 08:29:12, Uri Blass wrote: >On June 04, 2002 at 07:17:03, Vincent Diepeveen wrote: > >>On June 04, 2002 at 02:33:55, Russell Reagan wrote: >> >>I have been wasting a lot of time in search past years. >> >>Like last months i have wasted my time working on forward pruning. >> >>Sure i can search 3 ply deeper with it (and kicking out singular >>extensions and other extensions). >> >>However if i do that, then it scores simply 20-25% worse in tests >>against commercial programs. >> >>The reason was not so hard to find for me. It simply goes for 1 >>move and stays with that move. The rest gets forward pruned. Chances >>to find a superb move is way smaller. > >In this case it is a bad way of using forward pruning. >The idea of forward pruning is to prune tactical blunders and not to prune >positional moves. Fritz7 is doing opposite of pruning tactics. It seems to only prune positional lines. Idem for junior. Junior only sees tactics deeper. It simply gives for a simple rook move like Rab1 (if b-file isn't an open file) 2 ply penalty (or better the move costs around 3 ply to make). IMHO frans might do this because he is focussed upon solving tactics. If i use a similar form of pruning which fritz6/deepfritz seems to use, then diep only goes score 20-25% worse. Of course 400 points stronger at tactics... >Forward pruning that is done only when you lose a lot of material and the >remaining depth is small enough is a productive forward pruning. > >This is the first pruning that I added to movei even before null move pruning. >I have some more conditions in my program to help it not to miss sacrifices >by that pruning and I found that this pruning helped Movei to be better not only >in games but also in test suites. > >Uri
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.