Author: Antonio Dieguez
Date: 12:12:19 05/10/00
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On May 05, 2000 at 04:39:51, James Robertson wrote: >On May 05, 2000 at 04:01:13, Jan Pernicka wrote: > >> Hi, >>I would like to know what kinds of pruning are known (and/or used). To be >>correct, I don't mean alfa-beta (which is safe), but I mean rather kinds of >>forward-pruning(FP) (ie: not always safe...). I use this one: when it's last ply >>to horizon AND eval()>=beta AND not in check THEN return eval(). Are there >>several (probably more brutal (?)) techniques in use (except null-move)? > >I think the below is more common as far as fp. The 50 can be any arbitrary >value, but in my opinion it should be at least 25. Just returning eval(), as in >your example, is possible too. > >if (depth == 1 && eval() - 50 >= beta && !incheck()) return -quiesce(); hello, i suppose you wouldn't return inmediately -quiesce if it is below beta! also if your eval says about the available captures you could think about prunning inside this if, instead of evaluating the position ever again on the quiesce. >Of course you can also try extended futility pruning and even extended extended >futility pruning. I would recommend DarkThought's webpage, as that is where I >learned most about pruning. > >James of the rocket team? :) >> Thanks in advance >> >> Jan >> >>PS: But FP is very risky because (IMHO) better still to play average moves >> than excellent ones (but to make occasionally immediately loosing moves...) I dont understand what are you saying with that, but as in the darktought page is said, it works good in practice... me.
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