Author: Tony Werten
Date: 04:41:49 10/23/03
Go up one level in this thread
On October 23, 2003 at 06:19:14, Uri Blass wrote: >On October 23, 2003 at 05:34:29, Tony Werten wrote: > >>On October 23, 2003 at 04:43:31, Sergei S. Markoff wrote: >> >>>Hello! >>> >>>>In case you forgot, the evaluation can just return 1 score >>> >>>Oh when I was such simply guy >>>Than I was clean and brave :) >>> >>>>score it can't return 2 scores for either positional or tactical matters. >>> >>>The matter is not about the returning more than one score in search. The matter >>>is to use eval disequilibrium in current node to make some descisions. It can >>>affect search or evaluation itself. >>> >>>But, anyway, it's not impossible to use two scores. One example Centaur program >>>which uses two evals - pessimistic and optimistic. It's allows to produce good >>>cut-offs where optimistic eval < alpha or pessimistic > beta. I don't know >>>detatil but it seems to be interesting concept. >> >>Not really. It has been used for years, only most people use the term lazy eval. >> >>Pessimistic score: simple eval-maximum positional score >>Optimistic score : simple eval+maximum positional score > >This is not what I think about when I read pessimistic and optimistic. > >By this definition the difference between passimistic and optimistic is >constant. It doesn't have to be. After doing a full eval, you can check with the simple eval if the difference is bigger than the maximum pos. score and adjust it. In addition, you can use different maxposscores, fe maxposscore with x pieces on the board, maxposscores with and without passed pawns etc. Tony > >I think about calculating 2 bounds when in quiet positions the difference >between the bounds is small when in not quiet position the difference is big > >Uri
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