Author: Ross Boyd
Date: 02:21:30 04/19/05
Go up one level in this thread
On April 18, 2005 at 22:55:31, Uri Blass wrote: >On April 18, 2005 at 22:41:37, Uri Blass wrote: > >>On April 18, 2005 at 22:29:09, Uri Blass wrote: >> >>>On April 18, 2005 at 21:32:59, Jeremiah Penery wrote: >>> >>>>On April 18, 2005 at 07:24:11, Uri Blass wrote: >>>> >>>>>part of the problem is check extensions and part of the problem is probably >>>>>pruning based on evaluation together with other factors that I should improve. >>>> >>>>Why should check extensions make any difference in this position? Neither side >>>>should be giving any checks. >>> >>>The problem is that most of the search time is not on the right line but in what >>>happens after queen promotion. >>> >>>Movei cannot find the knight promotion in a reasonable time(I did not try more >>>than 30 minutes on a fast PC) but almost all the search time is on queen >>>promotion. >>> >>>After performing the knight promotion finding the mate is easy for movei. >>> >>>Uri >> >>Note that check extensions was only a thought and I am not sure that it is the >>problem. >> >>single reply extensions after queen promotion may be a bigger problem(single >>reply extensions are done also after a knight promotion but they do not help >>much because depth reductions that is not null move pruning are also used and >>probably they are used more after knight promotion). >> >>Uri > >Checking show that you are right that check extensions are not the problem and >single reply extension is the problem that prevent movei to go deep because >after queen promotion there are a lot of moves that force single reply that are >not checks. > >Uri :-) That sounds like the cause of the problem. The tree would explode. Do you limit single replies in any way? In 99% of positions its not going to be a problem anyway, so no need to fix it. Maybe put a hard limit of 4 non-check extensions or whatever works best. Ross
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