Author: Robert Hyatt
Date: 12:18:12 01/21/00
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On January 21, 2000 at 14:45:27, J. Wesley Cleveland wrote: >On January 20, 2000 at 18:12:20, Robert Hyatt wrote: > >>On January 20, 2000 at 11:46:44, leonid wrote: >> >>> >>>And how many plies, approximately, must be searched before the null-move will be >>>used? In what part of the game (or average number of moves per ply) and for what >>>computer speed you indicate your number of plies. >>> >>>Leonid. >> >>There is no magic number, and no easy answer. The problem is that R=2 hides >>two plies. If you do a 5 ply search, you can try a null at ply=3 and all you >>can do after that is a capture search. Which hides a lot of threats... and the >>threats are so close to the root that you might not be able to avoid them after >>making the move at ply=1. At depth=8, you still hide 2 plies, but you have >>4 more to find the threats. At depth=12, it gets better... because you push >>the ugly errors off farther into the tree, where you have (hopefully) more >>alternatives to avoid potential problems by varying at one of several different >>points in the tree... >> >>I used to get murdered with R=2 when I was doing 5 plies in blitz. I now do >>10-11 in blitz and don't see a problem at all that I have noticed... > >Have you tried using differing Rs at differing depths ? I have been for 2 years now. R=3 closer to the root, R=2 closer to the tips... to address the very problem I mentioned... There are other things to do as well, such as with reduced material, avoid any null moves near the root, so that the null-move failures are pushed away from the root by a significant margin. No null moves if the side on move doesn't have a piece. Etc...
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