Author: Robert Hyatt
Date: 13:43:40 09/28/98
Go up one level in this thread
On September 28, 1998 at 14:33:38, John Coffey wrote: >On September 28, 1998 at 14:20:58, Robert Hyatt wrote: > > >>> >>>I have asked repeatedly if we only do the null move check when up material, >>>and I have been told repeatedly that it is done everywhere. >> >> >>this is correct... >> >> >> > >but "everywhere" doesn't mean when you are down in material or the >material is even? it only means when material has been *gained*? > >Would there be an advantage to doing a SEE to eliminate some of >the garbage movies? I.e. Qxh7 might be a brilliant sacrifice, but >if the rook can take the queen then chances are it is a dud most >of the time? This is called "forward pruning" where you discard moves without ever searching them. Think of all the queen sacrifices that lead to mate, or the number of Bxh7+ moves that lead to mate, but which appear to lose the bishop to a simple SEE analysis... As far as the null-move search goes, it works in lots of mysterious ways. From the previously-discussed case where one side sacs material and the null move greatly shortens the searches below that node, to the more mundane case where oneside obtains a big positional edge and nothing the opponent can do (with two consecutive moves) to compensate for that positional edge...
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.