Author: Daniel Shawul
Date: 02:22:54 05/05/04
Go up one level in this thread
On May 05, 2004 at 05:16:49, Uri Blass wrote: >On May 05, 2004 at 05:06:43, Daniel Shawul wrote: > >>On May 05, 2004 at 05:01:55, Uri Blass wrote: >> >>>On May 05, 2004 at 04:40:43, Andrew Williams wrote: >>> >>>>On May 05, 2004 at 03:03:15, Daniel Shawul wrote: >>>> >>>>>Hello >>>>> >>>>>Is incremental attack table slower than creating them on fly? >>>>>I have both versions working properly right now but the incremental >>>>>one further drops NPS by 30% , though InCheck and Checks are for free in this >>>>>case. Anybody have similar experience? I am sure i have made no mistake in >>>>>updating because i checked it with the known perft positions and node count is >>>>>perfect. >>>>> >>>>>best >>>>>daniel >>>> >>>>It's a very long time since I implemented them, but at the time I compared the >>>>incremental ones were faster. I can't remember exactly how much faster it was, >>>>but I think it was of the order of 10 to 15%, if only because that is what a >>>>comment in an old source file says. What I don't know is if this was *after* >>>>thorough debugging. >>>> >>>>Andrew >>> >>>I have different attack tables. >>> >>>Last time that I implemented incremental tables was a long time ago before I had >>>a chess program. >>> >>>I did not make notes to see how much faster it was but it was more than being >>>1000% faster in calculating perft. >>> >>>Uri >> >>How can incrementally updating attack tables make perft faster? > >I need the attack tables to generate legal moves. > >I have a function that generates the legal moves and it is dependent on the >tables. > >My tables tell me if a square is attacked by the opponent so I do not generate >moves that put the king in check. First you update the attack table with the move and then you generate only legal moves based on the attack tables , right? What i do is update the attack table and then generate "pseudo legal" moves,except king moves to an attacked square. So our difference is you have a routine which calculates only legal moves based on your attack tables. I don't see how that can speed up perft immensely. daniel > >My tables also tell me the directions that a square is attacked and the square >of the attacker from every direction so in case that the king is attacked I have >a special function to generate moves that is using this information. > >I never had move generator that is not dependent on the tables and makemove >always updated the tables. > >Uri
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