Author: Frank Phillips
Date: 13:54:10 11/27/02
Go up one level in this thread
On November 27, 2002 at 15:54:26, Omid David Tabibi wrote: >On November 27, 2002 at 15:36:31, Frank Phillips wrote: > >>On November 27, 2002 at 15:15:50, Robert Hyatt wrote: >> >>>On November 27, 2002 at 13:48:50, Frank Phillips wrote: >>> >>>>On November 26, 2002 at 20:02:06, Robert Hyatt wrote: >>>> >>>>>On November 26, 2002 at 16:21:00, Omid David Tabibi wrote: >>>>> >>>>>>On November 26, 2002 at 15:58:06, Gian-Carlo Pascutto wrote: >>>>>> >>>>>>>On November 26, 2002 at 15:55:56, Omid David Tabibi wrote: >>>>>>> >>>>>>>>So it is reasonable that on every program starting from a certain depth >adaptive null-move pruning will always construct a smaller search tree. >>>>>>> >>>>>>>Don't you mean the other way around? >>>>>>> >>>>>> >>>>>>Yes :-) >>>>>> >>>>>>Starting from a certain depth, verified null-move pruning will always construct >>>>>>a smaller search tree than the adaptive one. >>>>>> >>>>>> >>>>>> >>>>>>>-- >>>>>>>GCP >>>>> >>>>> >>>>> I am doing some testing now. First thing I noticed is that for WAC, the >>>>>time-squared >>>>>measurement went down very significantly for your algorithm. And I have not >>>>>modified >>>>>anything such as turning null-move off when low material happens, since your >>>>>idea will >>>>>catch the zug problems. >>>> >>>>Have you tried Fine70? >>>> >>>>Frank >>> >>>Yes... and I told Omid that this is a strange case as if I allow null-move in >>>pawn-only >>>endings, which turns it on for fine 70 of course, things get wrecked inside the >>>search >>>somehow. A 45 ply search fails to see that Kb1 wins where normally an 18-19 ply >>>search is enough... >>> >>> >>>>> >>>>> >> >> >>Snap... and I have no idea why. I thought it was my implementation of a similar >> idea (from Bruce's site) of verification search, but I copied the scheme in >>Omids paper and it does the same. >> > >What appears at Bruce's site is the original Goetsch and Campbell idea to detect >zugzwangs. Plenkner (1995) introduced a similar zugzwang detection method. > >Verified null-move pruning is different from these methods, for its most >important application is in middle games, constructing a smaller search tree >with greater tactical accuracy. > > >>Frank Got it. It is not recursive (of course) so the non-verified null moves can fall prey to zugswang. Frank
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