Author: Michael Henderson
Date: 17:33:45 09/05/04
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On September 05, 2004 at 20:08:07, Stuart Cracraft wrote: >Odd improvement... > >I had used see within quiescence to discard moves >< 0 of see value (losing combinations) and those >that didn't make it past a certain margin (futility >cutoff / delta pruning). > >At the time I had added a capability in the move >generator when a move is added that scored any >capture with see and stored it for later use. >This was then used in the quiescence as above >for discarding, avoiding using the generate there. > >But because of having to do the see for each move >in the main search, the net result was worse performance >on test suite, not better. > >So I just made a separate routine to keep the see() running >completely out of the main search, do it for all capture >moves all the time in quiescence but at time move is added >to movelist instead of at time move is searched. This resulted >in 1% improvement in score: > >wacnew > >**** 6.80/23.83 80% 240/300 250.67 73082144 243607/1/291553 0/871282/397085/1606 >781/18010090/63447 > >wacnew with the see() call in movelist routine instead of quiescence, >but still used in quiescence > >**** 6.81/27.35 81% 244/300 249.71 74112552 247042/1/296798 0/854177/1447453/515 >821/17298092/99799 > >Not quite sure why this occurred. There may be some other confounding factor >that I just got lucky with when making the change. > >I looked more carefully and saw a side change I had made was simply to add >the "see" score into the mvv/lva and then make that the pre-search score >of the move from the move-generation routine. > >Previously, mvv/lva was used only, unless the global see() use in move >generation for all captures for both main search and quiescence search was >used. > >Now, see score is added in, with mvv/lva, in move generation, for all captures >but only in quiescence -- see is not used in main search. > >Anyway, add your see score in like the above and see if you experience >a small jump, rather than just using <0 to decide whether to cut. You >get the benefit of the sort, helping the move ordering. > >I speak only to the ones who didn't do this already. > >Stuart Are you doing 1 second searches?
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