Author: David Dahlem
Date: 14:11:30 12/28/05
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On December 28, 2005 at 16:24:53, Dann Corbit wrote: >On December 28, 2005 at 16:03:47, David Dahlem wrote: > >><snip> >> >>>If you have a bitboard program, there is a way to get really cheap mobility >>>scores. >> >>Could you elaborate on this method? > >Precalculate for every ray, based on the bit pattern on that ray. > >Move generation is also helped by this idea (both for capture/promotion and >non-capture). > >consider this epd string: >[D]4k3/1n6/8/pR5b/1P6/1n6/1N6/4K3 w - - >For the rook's row, we have 1x000001 ( the x is because we ignore the square he >sits on, he can never attack or defend that.) >For this simple case, the non-captures are the zero squares and the captures are >the non-zero squares anded with the opponent chessmen mask. >Regardless of what the chessmen are, there are 5 non-captures and 0,1,or 2 >captures depending on whether the 1 bits are friend or foe. > >For the column we have 010x1110. >There is one non-capture and 0,1, or 2 captures depending on whether the nearest >one bits are friend or foe. > >You get the idea. Thanks Dann. Mobility should only be considered for bishops, knights, rooks, and queens, is this correct? And I'm thinking the bonus should be scaled according to piece values? Regards Dave
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