Author: Roman Hartmann
Date: 13:25:08 12/28/05
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On December 28, 2005 at 16:04:28, Tord Romstad wrote: >On December 28, 2005 at 15:31:55, Roman Hartmann wrote: > >>On December 28, 2005 at 15:27:34, Dann Corbit wrote: >> >>>How are you calculating mobility? >>>A 10:1 loss in speed is very traumatic. >>>Unless you are only counting wood in your evaluation, you should not see that >>>traumatic of a degradation. >> >>Several problems: >>-outdated board design 10x12 > >16x12 may be slightly more convenient, but 10x12 isn't outdated >at all. There is no reason why mobility evaluation should be expensive >on a 10x12 board. I only learnt recently about the 0x88 move generation sheme on Bruce Morelands nice site. I guess I mainly wrote that in order to talk myself into rewriting the movegenerator. >>-legal move generator instead of pseudo legal > >You shouldn't generate moves at all when evaluating mobility. This >is almost certainly the main reason why you see such a big slowdown. >When you generate moves, you do a lot of work which is not necessary >when you just want to evaluate mobility. You don't need the moves >at all, just the number of moves. If the mobility thing pays out, I will definitely take care of that problem by adding a second move generator that only counts the moves but doesn't store them. >Perhaps you can even omit some >piece types. I don't evaluate pawn or king mobility at all (in my >experience, there are better ways to evaluate king activity), and I >have never seen any measurable difference in strength when I >switch queen mobility on or off. Thanks for that info. So far the version with mobility scores 228/300 in WAC (5s per move) while the non-mobility version scores 254/300. But that doesn't tell much about the positional play, of course. And probably I also didn't found the right weighting for the mobility-factor yet. Roman >Tord
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