Author: Robert Hyatt
Date: 11:06:12 03/03/06
Go up one level in this thread
On March 03, 2006 at 02:42:48, Tony Werten wrote: >On March 03, 2006 at 00:36:19, Robert Hyatt wrote: > >>On March 02, 2006 at 02:14:56, Tony Werten wrote: >> >>>On March 01, 2006 at 16:05:06, Robert Hyatt wrote: >>> >>>>I am still using my old 12-bit history index <to><from> to index into these new >>>>values. I also still maintain one for white and one for black. I once tried a >>>>17 bit index <piece><to><from> but it offered no improvement to the basic >>>>history heuristic, but I have not tested that with this reduction stuff. >>>> >>>>Any ideas what others are doing here? I can think of several possibilities: >>>> >>>><piece><to> >>>> >>>><piece><from> >>>> >>>><to><from> (I am doing this now) >>>> >>>><piece><to><from> >>>> >>>>to name at least 4. First two seem too simplistic. Last one turns the history >>>>tables into pretty good sized arrays (2^17 for white, ditto for black). >>>> >>> >>>It does only once if you use this to index a second table which returns an index >>>only for actual legal moves. >>> >> >>Not sure I follow??? "actual legal moves"??? > >If you use piece-from-to (12*64*64=49,152 entries) a lot of your array can only >be filled with moves like Qa1-b8 and the like. OK. Now I understand what you were talking about... wasted space... > >Using a secondary table wich only has an index if the move is legal, will result >in a moveindex range of about 4000. > >Now every table you use based on the moveindex only has to be 4000 in size >rather than 49152 when you base it on the move. > >It can be used for the obvious stuff (history table,fh stats etc) but also for >more interesting things (fast semi possible move detection ie does it have an >index, piecesquare values of a move etc) > >Tony > >> >> >>>Tony >>> >>>>Note that I am essentially factoring in wtm already since I have two separate >>>>sets of history tables for black and white.
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