Author: Will Singleton
Date: 15:20:01 11/28/00
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On November 28, 2000 at 16:06:11, Bruce Moreland wrote: >On November 28, 2000 at 14:06:27, Andrew Williams wrote: > >>On November 28, 2000 at 12:52:57, Scott Gasch wrote: >> >>>Hi, >>> >>>I posted a couple of messages about move ordering yesterday and wanted to share >>>some results from my (limited) testing. I ended up implementing the suggested >>>"apparently losing captures" (MVV/LVA) after all others order. In one test >>>position this resulted in a tree 200k nodes larger at 8 ply but in two others it >>>resulted in a marginally smaller (under 40k nodes) tree at 8 ply. I will do >>>more testing on this matter but it may be a moot point because I intend to write >>>a SEE pretty soon. >>> >>>I also did some experimenting with ordering captures that take the last moved >>>enemy piece. At low search depth this seems to make some difference but at >>>higher depth this heuristic actually grew the tree in all three test positions > I tried. >>> >>>I also did some playing with history weight and settled on hist[x][y] += (2 << >>>depth). >> >>I use history[whoseTurn][frsq][tosq] += (depthremaining*depthremaining) >>I have a separate table for white and black. Every few plies I divide >>this number back by a lot (can't remember how much or how often). > >Why does everyone think that a move that cuts off after a deep search is more >likely to produce cutoffs elsewhere in the tree, than one that cuts off after a >shallow search? > >That multiplication is expensive. Does it achieve anything? > >bruce How expensive? I've got multiplications and divisions all over my program. I never thought it would amount to more than a few nps. Will
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