Author: Alessandro Damiani
Date: 15:20:44 09/08/99
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On September 08, 1999 at 14:30:12, Robert Hyatt wrote: >On September 08, 1999 at 13:37:31, William Bryant wrote: > >>On September 08, 1999 at 11:20:54, James Robertson wrote: >>> >>>I have had a terrible time trying to implement something like this, and finally >>>gave up. How much does it help Crafty/Screamer? Is it worth it to try to get it >>>to work? >>> >>>James >> >>I also had a terrible time until I finally worked out the errors, and there were >>several. The problem lies in how to structure the aspiration windows, >>the researches for fail-high and fail-low, and then adding PVS searching on top >>of it. >> >>Bob and others were a lot of help. >> >>My problem now is that my SEE seems to be pruning to much. On rather quiet >>lines, it does a great job of getting to the next ply. On positional issues, >>it makes the program play much poorer. >> >>For Example, on LCT-II the POS part of the suite, the score drops in half, >>missing several of the answers with the Delta-SEE pruning in place. It makes up >>some of this in the tactical middle game portion. >> >>When playing the two versions against each other, at short time controls >>(2s/move), the SEE version clearly dominates. At longer controls (5-10s/move or >>greater), the slower more positional version does better. >> >>I am operating under the assumption that there is a bug somewhere and that >>eventually the SEE will give me the speed without sacrificing the positional >>skill. >> > > >I have done a lot of testing here, and I don't notice any particular positional >'drop-off' with SEE on or off, other than the fact that it gets me almost one >more ply since it reduces the q-search by over 50%. > >You might have your 'delta' window too narrow. Of course, making it too wide >disables the pruning... so, like Goldilocks and the three bears, you have to >get it "just right"... :) > > What is the 'delta" used for? Thank you. Alessandro > >>It is possible that the positional 'insight' is accidental, finding the right >>move without knowing why. >> >>Any insights in getting you SEE to work would be appreciated. >> >>William >>wbryant@ix.netcom.com
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