Author: Tony Werten
Date: 23:42:48 03/02/06
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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. 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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