Author: Uri Blass
Date: 03:26:16 11/21/02
Go up one level in this thread
On November 21, 2002 at 06:25:17, Uri Blass wrote: >On November 21, 2002 at 04:52:13, Omid David Tabibi wrote: > >>On November 20, 2002 at 22:05:29, Robert Hyatt wrote: >> >>>On November 20, 2002 at 16:55:41, Gian-Carlo Pascutto wrote: >>> >>>>Nullmove in Deep Sjeng uses an algorithm of my own, but I can >>>>switch it back to other systems easily. I did so for running >>>>a few tests. >>>> >>>>I made a version which uses Heinz Adaptive Nullmove Pruning >>>>and a version which uses your verification nullmove. >>> >>>This would seem to be a bit harder than at first glance. They say that >>>if the normal null-move search fails high, then do a D-1 regular search >>>to verify that, but while in that verification search, no further >>>verification searches are done, meaning that the normal null-move search >>>fail-high is treated just like we do it today.. >>> >>>I'm going to experiment with this myself, just for fun, but it seems that you >>>need to pass some sort of flag down thru the search calls indicating that >>>you are either below a verification-search node or not so that recursive >>>verification searches are not done... >>> >> >>Exactly!! (finally someone read the article carefully) >> >>See Figure 3 for detailed implementation (the flag you mentioned which is passed >>down as a parameter for search(), is called 'verify' in the pseudo-code). >> >>At first stage leave alone the zugzwang detection part (the piece of code at the >>bottom of Figure 3). Due to instablilities, some programs might do a needless >>re-search. First let the algorithm work fine in general, and then do the >>zugwzang detection part. > >I let the algorithm to work without zugwzang detection and first results seems >not to be good > >Some positions I get at the same depth and >the only position so far in the gcp test suite that I got at smaller depth for >tactical reasons is >[D]5rk1/1r1qbnnp/R2p2p1/1p1Pp3/1Pp1P1N1/2P1B1NP/5QP1/5R1K w - - 0 1 > >I am going to try it in 10 sedconds per move and get resulkts in half an hour. > >Uri should be seconds,results,position I type too fast. Uri
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