Author: J. Wesley Cleveland
Date: 18:11:01 03/02/01
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On March 02, 2001 at 16:56:11, Severi Salminen wrote: >>>Yep, that's true. As Bob said it is very rare to have beta=INF. Actually >>>Beta=INF can occur only in the very beginning of the search until we get our >>>first real score (score<=INF-Ply). Remember also that you don't have to know >>>anything else about the nullmove but whether its score is >=beta. So you can >>>search with (-beta,-beta+1) >>> >>An idea I had, is that since about half the time we expect a move to fail low, >>it doesn't make much sense to give the opponent an extra move and expect it to >>fail high. > >Well, the point is: how do we know it _before_ trying the null move? Futility >(pre) condition is one good indicator: if(depth==1&&material+MARGIN<=alpha). > We know from where in the search we are, e.g. if the move being considered is off tje PV, we expect a fail high, and should try nullmove, but the response to this move should fail low, and nullmove is a waste of time.
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