Author: David Hanley
Date: 16:51:35 11/29/01
In my program i decided that instead of calculating the material balance at each leaf i can just adjust it at each capture/promotion. That seems to work pretty well, and i figured that an average on one op per inside node would be a lot cheaper than 64 per leaf. I realized later that many leaves will be reached with material balances far outside alpha & beta. So, my thinking was to write code much like the following: if ( material < ( alpha - (2*pawn))) return alpha - 1; if ( material > ( beta + (2*pawn))) return beta + 1; Since i'm assuming positional factors will not exceed 2 pawns, i think this should not change the reults ever, and the values alpha-1 and beta+1 should not affect the search, falling outside the window, as it were. Now this does complicate quiescence a bit, but i think it's still something i can sort out. I was thinking furthermore that i can do a lot of the positional eval ( central control, pawn advancement, etc ) during the search. That way, i can probably get a much more acurate compute-free guess at the current positional score, and short-circut positions less outside alpha & beta. Seems like a pretty straightforward technique, but i've not heard of it before. Is it fatally flawed? I don't recall seeing it in a book or in someone's sources. dave
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