Author: Robert Hyatt
Date: 17:14:46 10/20/97
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On October 20, 1997 at 09:45:52, Reinhold Gellner wrote: >On October 20, 1997 at 08:52:02, Chris Whittington wrote: > >> >>On October 20, 1997 at 02:29:25, Reinhold Gellner wrote: > >>>To eliminate that problem, try increasing the search depth by 2 ply >>>every iteration. >> >>This is a surprisingly well used solution. >>But increasing by 2 each iteration loses much of the advantage of >>iterating (guided search and 'small' incrementally deeper researches). >>You need to jump by two every two iterations, and find a method for what >>to do in the 'gap' iteration. >> >>Its also an advantage for an exchange-evaluator to stop on odd plies, >>rather than even. Its decisions that an as yet untaken piece is actually >>lost will be better taken if the piece is a computer piece (odd ply) >>than a human piece (even ply). Asymetric safety factor skandal for >>Komputers !. >> >>Best then is to jump by 2 ply every two iterations and use a pruning >>function over the final plies that is strong pruning the first iteration >>and weaker pruning the second - then jump two plies again and so on. >> > >2-ply-jumping is not neccessarily more stable than 1-ply-steps, because >the jumping "distance" is simply one ply more. If you are doing >sophisticated prunings, e.g. part-ply prunings, together with >part-ply-extensions, then perhaps half-ply-iterations might be worth >considering. > >At the moment I can live with smooth oscillations jumping allways one >ply. > >Reinhold The only known "production" program doing this was "BeBe" by the late Tony Scherzer. he did odd ply searches only, as he liked the "aggressive" behavior of odd plies. But it costs quite a bit, particularly if you have enough time to do 8, but not 9. So you settle for 7...
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