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Subject: Re: late move reductions (and another question)

Author: Tony Werten

Date: 23:52:15 03/02/06

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On March 02, 2006 at 12:15:05, Dezhi Zhao wrote:

>On March 02, 2006 at 11:43:20, Robert Hyatt wrote:
>
>>On March 02, 2006 at 01:08:47, Dezhi Zhao wrote:
>>
>>>If you want to try adding another dimension to the history table, I think the
>>>ply number is the best candidate. You just replace the side index with the ply
>>>number. This will greatly localize the histroy table and probally make it more
>>>useful. We can call it history killer table by doing so:)
>>
>>Huge table.  becomes 4096 * 64 for my program. = 2^18 or 262K entries...
>>
>
>you may use [ply][piece][to], 64*12*64 = 48K entries. and only the very first
>quarter of the table is really active most of the time. So, this looks not that
>bad.

Actually, it's only 24K. If you have the plynumber, you don't need to
distinguish between black and white pieces.

Tony

>
>>I'll add this to my list of things to try however, although I suspect it will
>>only be useful for the reduction test, since the point of global history
>>counters is to emulate a sort of global killer move list...
>>
>
>Yes. I understand history table is in fact a set of global killers. However,
>[ply][piece][to] or [ply][from][to] obviously dominate your original
>[side][from][to]. If you still need the globalness, just add all the history
>values of a move from odd plys and even plys respectively.
>
>
>>
>>>
>>>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).
>>>>
>>>>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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