Author: Ed Schröder
Date: 05:46:56 01/07/03
Go up one level in this thread
On January 07, 2003 at 07:31:35, Tony Werten wrote: >On January 07, 2003 at 07:17:27, Ed Schröder wrote: > >>On January 07, 2003 at 06:48:50, Tony Werten wrote: >> >>>On January 07, 2003 at 05:47:37, Ed Schröder wrote: >>> >>>>On January 07, 2003 at 05:05:31, Tony Werten wrote: >>>> >>>>>Hi Ed, >>>>> >>>>>your board tables seem to ignore xray attacks. >> >> >>>>xray attacks are done, it's only not mentioned as I thought it would be >>>>self-understood. >> >>>I don't see how they are combined with the boardtables to find hanging pieces. >>> >>>Adding them as normal attacks will make you go wrong as often as not counting >>>them at all, is my guess. >> >>Let's go through a couple of xray examples: >I understand (I think). Ignore low pieces through high pieces, but add high >through low as a normal attack. Seems a cheap way. One question though. Will it >go wrong in this position (g8) ? Rebel will report that G8 is hanging, expected gain 5.00 It's all in those bits, there are a few complicated cases you don't get the right status, but over 99.9% will get it right. Ed >[d]r2qkbqr/pbppp1pp/1pn2p2/3Q4/2B5/2P1P3/PP1P1PPP/RNB1K1NR b KQkq - > >Tony > >> >>[d]rn1qkbnr/pbppp1pp/1p3p2/8/2B5/1QP1P3/PP1P1PPP/RNB1K1NR b KQkq - >> >>The knight on G8 is hanging, 2 attackers, one defender, the lowest attacking >>piece is a bishop. You can extract this from the bit settings. >> >> >> >> >> >> >> >>[d]r2qkbnr/pbppp1pp/1pn2p2/3Q4/2B5/2P1P3/PP1P1PPP/RNB1K1NR b KQkq - >> >>The knight on G8 is not hanging because the lowest attacking piece is a Queen. >> >> >> >> >>[d]rn2kbnr/pppqpppp/3pb3/8/8/P1N4N/1PPPPPPP/R1BQKB1R w KQkq - >> >>The white knight on H3 is well covered, 2 attackers, 2 defenders, the lowest >>attacking piece is a bishop, but its defender is lower, a pawn. The white bishop >>on F1 looks through G2 to H3. >> >>Hope this helps, >> >>Ed >> >> >> >>>Tony >>> >>>> >>>> >>>>>Is that because it doesn't matter too much, or because it's mainly used for move >>>>>ordering ( so it's only less effective but not wrong ) ? >>>> >>>>I use xray also for evaluation, for instance for mobilty, king safety, so xray >>>>must be done and in an accurate way, I will write a little about it in the >>>>mobility section. >>>> >>>>Ed >>>> >>>>>Or do you handle xray attack as a normal attack ? >>>> >>>> >>>>>Cheers, >>>>> >>>>>Tony
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