Author: Ernst A. Heinz
Date: 03:31:37 03/18/98
Go up one level in this thread
On March 17, 1998 at 21:42:52, David Blackman wrote: >Actually about positions like KNkp and how thay should be evaluated. > >It looks like Junior, Crafty and maybe others are evaluating such >positions >as not winnable as soon as they appear in the tree. Surely it would be >better >to allow the tree to grow out to its normal depth, and just detect these >(probably drawn) positions in the normal end-node evaluator. That way >your program "knows" it is a draw, unless the win is shallow enough to >see in the search, in which case it finds it. > >Of course that makes the search tree a bit bigger for a given depth. >Has anyone tried both approaches to see how big the cost is? "DarkThought" uses fast rules of thumb to disable the draw detection heuristic in such cases where it might fail. The costs are negligible -- both as for runtime overhead and size of search tree. "DarkThought" solves all the critical positions posted in this thread. W.r.t. Christophe Theron's analysis of the Nolot-Position with key move Ng4 I like to add that for "DarkThought" the depth where it finds the solution not only depends on the null move search but also quite strongly on the aggressiveness of pawn-related extensions. =Ernst=
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.