Author: Stuart Cracraft
Date: 10:38:23 08/21/04
Go up one level in this thread
On August 21, 2004 at 13:36:50, Michael Henderson wrote: >On August 21, 2004 at 13:20:11, Stuart Cracraft wrote: > >>All, >> >>SEE increases my nominal iteration depth by 0.42 pawns >>given the same amount of time as a non-SEE search, all else >> >>SEE decreases my max quiescence depth reached (with a check handoff >>to main search) by a little under 8 ply for the same problem set. >> >>These are the 300 positions from Win-at-Chess run at 1 second per >>problem on an old, slow, notebook. I do not have comparative data >>due to the subjectivity involved of chess games and the "feel of SEE". >> >>Legend: >>Ave Iterative Depth/Average Max Search depth >>% solved >>Total solved / Total in test >>Total time taken (300 seconds allowed) >>Total Nodes searched >>Average positions searched per problem / >>Average time (rounded) per problem / >>Average nodes per second per problem >>0/0/Check Extensions from Quiescence back to Main Search/0/0 >> >>Without SEE >> >>**** 6.68/27.18 68% 204/300 269.05 54264704 180882/1/201692 0/0/3361112/0/0/0 >> >>With SEE >> >>**** 7.10/19.01 64% 193/300 267.44 46135172 153784/1/172505 0/0/1154026/0/0/0 >> >>Total problem solution rate drops 5.4% and nodes searched drops 14.98% >> >>(The SEE being used above was tried as (1) see < 0 then don't search >>a capture move in quiescence and (2) see < delta where delta is calculated >>with its margin off alpha as the maximum positional score so far in the >>search for the side on move. The above results are the combination of both and >>if only using the #2, assuming for example my SEE is not a great SEE, >>the result is only slightly changed.) >> >>My question is, why should SEE reduce the tactical result so drastically >>and is it safe to do so given the depth and nodes results are favorable? >> >>Thanks ahead, >> >>Stuart > >SEE cuts losing captures and WAC may involve "losing captures" (scored by SEE) >as the winning moves. Try running the test at more than 1 sec/move. The extra >speed and depth you gain from SEE (cut qsearch) will probably equal or outweigh >the "losing" but winning captures pruned from SEE. Be aware that SEE is very >safe and effective to use in quiet positions but not so much in tactical >positions (unless you let it run longer). > >Michael Interesting. I should probably disable it for slow PC's or short time settings.
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