Author: Stuart Cracraft
Date: 16:24:01 08/21/04
Go up one level in this thread
On August 21, 2004 at 17:52:58, Robert Hyatt wrote: >On August 21, 2004 at 17:37:15, Stuart Cracraft wrote: > >>On August 21, 2004 at 17:23:30, Robert Hyatt 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 should _help_ in tactics, not hurt. If it is hurting, there is something >>>wrong somewhere... >> >>That's puzzling. I've tested it pretty thoroughly, manually, in a variety >>of positions and think it is working right. It knows nothing of any secondary >>effects, just the exchanging pieces. No x-rays, etc. >> >>Now I'm really nervous. > > >No x-rays is a serious shortcoming. IE two rooks attacking the same square in >battery. If you don't include the second rook I could see how SEE could cause >problems. I handle X-rays pretty easily and always did even back in CB days... Yes -- X-rays have to be added. Finding them isn't a problem. It's what to do with them after. I'll check around.
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