Author: Komputer Korner
Date: 15:24:25 08/03/98
Go up one level in this thread
On August 02, 1998 at 15:56:18, Don Dailey wrote: >On August 02, 1998 at 14:38:28, Komputer Korner wrote: > >>On July 31, 1998 at 12:26:57, Amir Ban wrote: >> >>>On July 31, 1998 at 09:34:58, Komputer Korner wrote: >>> >>> >>>> >>>>I believe that Fritz 5 is a full width searcher with an excellent null move >>>>algorithm. In fact the manual says it is a full width searcher. >>>>-- >>>>Komputer Korner >>> >>>Don't understand your meaning. It certainly uses some extensions, and it uses at >>>least null-move for forward pruning, so it does both extensions and pruning like >>>the rest of us. So what does the "full width" bit mean ? >>> >>>Amir >> >>The full width means that it does consider every move and doesn't prune these >>out at an early ply. AS you know every selective searcher does full width to >>some minimum ply depth, but full width searchers will still calculate every PV >>at a deep ply level. BTW, what would you classify Junior as? >>-- >>Komputer Korner > >KK, > >I disagree with your definition of full width. Fritz is about as >selective as any program I know. As soon as you do a null move >you fail to be full width, since the resulting position is not >a normal position. You are actually doing a test for selectivity >to see if you will persue a given line of play. In effect, Fritz >does not even do a full width 1 ply search since no quies is actually >performed on some of the moves. > >The depth reduction of null move makes it seem as if you are really >doing reduced depth full width searching, but the reality is that >you are not, although the effect is quite similar. > > >- Don We are getting hung up on the null move issue. Crafty uses null move but is still a full width program. CM 5000/5500 and Rebel 9 are selective searchers. Yes null move is a form of selectivity, but it is so common even among the full width programs that I discount it as a test of whether a program is selective or not. -- Komputer Korner
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