Author: Gerd Isenberg
Date: 13:36:42 01/20/06
Go up one level in this thread
>I have not read any formal BB technique, too tough. So I just go ahead armed >with x & -x, x & x-1, x - y > 0 to get intervening bits, bits_E/LE/G/GE etc.. > >I now cannot see how any BB engine can be efficient w/o incremental updates of >all (sliding) attack maps of the b/r/q. The complete attack info is an >incidental good bonus. I can only see that to extract Q-moves, we need the >complete q-attack map. If we generate the Q-attack map anew at every node, we >need to manipulate all 8-rays. With incremental, at most 2-rays or none, need >updates. My 1-step-ahead IQ asks _how-to-be efficient? With rotated, four lookups for queenattacks with shifted or already raywise updated occupied states and square. Not that expensive. It might be very implementation depending - the number of nodes you need queen attacks (for both sides) and the number of nodes you don't need them or only for the side to move. > >May be the reason why Rybka quickly exchanges it's queen is not to deal with >8-rays. Vasik would likely go to trade all R-R, B-B, so nothing sliding to >worry. Then his Knight = 330, Bishop = 310, etc... Hehe - i don't think so. Regards, Gerd > >Best Regards >Rasjid
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