Author: Uri Blass
Date: 04:28:01 04/19/05
Go up one level in this thread
On April 19, 2005 at 05:21:30, Ross Boyd wrote: >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 I limit them but the limit is not based on their number but based on evaluation and if the side that force the single reply is clearly winning I do not extend. Uri
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