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Subject: Pondering and hashing

Author: Johanes Suhardjo

Date: 15:10:15 02/19/99


In the past, my pondering is just like my search, only it's done when the
opponent is thinking.  Recently, I changed it so that when pondering there's
no null move, no pruning, nothing risky, just plain alpha-beta.  The idea is
that maybe I can catch some positions that I miss in the regular search.

After reading some discussions on CCC, I start thinking that my pondering may
not be a good idea because the resulting hash entries may conflict with the
hash entries from the regular search.  I don't know how to check if this is a
good or dumb idea because I have only one computer so I can't play with other
programs with pondering on.  Yes, I have an account on FICS (parrot), but the
opponents there are very unpredictable, one day I may get lowly rated
opponents that play very well, the next day I may get the opposite, not to
mention that playing styles affect the outcomes of the games.

On a related issue, one idea that I'm trying is to use different alpha-beta
windows at the start of search when the position is tactical and when it is
not.  Running this on test positions certainly give better results, but in
real games I suspect the results are slightly worse.  That may have something
to do with inconsistencies in hash entries from different stages of a game.
I keep the hash tables all the time, maybe I should clear the hash tables
at the beginning of the search.  I definitely have to test this.

Any comment/suggestion?


                         Johanes Suhardjo (johanes@farida.cc.nd.edu)
--
Trying to establish voice contact ... please yell into keyboard.



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