Author: Robert Hyatt
Date: 13:19:29 02/28/06
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On February 28, 2006 at 14:48:10, Harald Lüßen wrote: >On February 27, 2006 at 22:22:55, Robert Hyatt wrote: >... >>4. the biggest thing I want to play with is the history values. I am currently >>"aging" the values between iterations, but what is happening is that the values >>climb faster as the search gets deeper, which tends to make it get more >>conservative as it goes deeper due to the history threshold limiting when >>reductions are done. Either the history values need to be stabilized, or >>perhaps the reduction threshold needs to climb along with iteration number... >>or something in between... > >When I read my history values I always get values between 0 (not good) >and 256 (most often successfull). I do this with saved history values >between 0 and 65536 and an additional maximum value which is always >updated. Then I can return (history * 256 / (maximum + 1)). When maximum >gets too big, all values and the maximum are divided by a factor. >This is not very precise but you can easyly fix the flaws and >find good tuning values for too big and factor. > >I do this because I want always be able to use the history >as input value for some formulas like reductions or margins. >Since my engine is not very good this might be a bad idea. ;-) > >Is it possible to make history pruning / late move reductions >depend on the whole history value interval or is it important >to use == 0 and != 0 only? > >Harald I have a threshold value that can be changed. 0/!0 seems _very_ conservative, whereas <N or >=N where N is greater than zero is more aggressive. The larger N, the more aggressive it is, but the more risky it is as well. If history_value[x] >= N no reduction, else do reduction; is the idea I am using as one of the qualifying/limiting conditions...
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