Author: Tord Romstad
Date: 08:47:25 07/28/04
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On July 28, 2004 at 10:09:19, Stuart Cracraft wrote: > >> >>In the qsearch, I prune futile captures with code that looks roughly like >>this: >> >>if(approximate_eval_after_move(move) < alpha-margin) >> prune move > >So the approximate eval after the move is simply a searchless eval? Yes. It's something like this: (static eval of current position) + (value of captured piece) - PieceSquareTable[moving piece][from] + PieceSquareTable[moving piece][to] + PieceSquareTable[captured piece][to] >What is your margin? It is not a constant, but depends on the position. In most positions it should be somewhere around 0.6-0.8 pawns, but it is increased a lot if there is a huge difference between the incremental eval and the full eval of the current position, or if the king safety or passed pawn components of the eval are big. Tord
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