Author: Tony Werten
Date: 04:14:12 04/22/01
Go up one level in this thread
On April 21, 2001 at 16:37:15, Alex Boby wrote: > >My PV search uses the assumption that when the minimal window search fails high, >then the score returned is at least as high as the true score which will be >returned when you search again with a wider a/b window. > >All was fine and dandy before hashing. Now I'm experiencing problems where this >assumption is incorrect because the score from the minimal window search was >returned via a hash table hit which was overwritten before the research takes >place. So the research doesn't return a score >= min window score. > >And so I'm unsure about how to deal with the PV search now when the base >assumption for that technique is invalid. > >Any suggestions are greatly appreciated :) > >Alex Boby I'm trying to solve this by researching in steps. If a new move fails high when searched with pvs (beta, beta+1) I research with (alfa, beta+200) (.2 of a pawn) so the move has to "prove" itself. If the score returns >=beta+200 then I research with full window (alfa,MAT_VALUE), if score >alfa and <beta+200 I count it proven and don't research, if score<=alfa I throw it away. It happens that a move first scores >=beta+200 and then when researching scores <=alfa but not very often. cheers, Tony
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