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Subject: Re: Creating Tablebases like the SETI-project.

Author: John Merlino

Date: 17:38:20 06/27/03

Go up one level in this thread


On June 27, 2003 at 18:02:44, Guido wrote:

>On June 27, 2003 at 16:37:23, John Merlino wrote:
>
>>On June 27, 2003 at 14:43:33, John Merlino wrote:
>>
>>>On June 27, 2003 at 08:25:28, Guido wrote:
>>>
>>>>On June 26, 2003 at 15:33:29, John Merlino wrote:
>>>>
>>>>>On June 26, 2003 at 14:12:32, Peter Stayne wrote:
>>>>>
>>>>>>Has anybody figured out how big a complete (w/ pawns) set of 6-mans would be.
>>>>>>And noone has completely rendered these yet right?
>>>>>
>>>>>Marc Bourzhutsky (sp?) is currently creating 6-man files in the de Koning format
>>>>>used by Chessmaster. When last I was notified of his progress (which was quite
>>>>>some time ago), he had well over 30 DVDs of archived data, but had only
>>>>>generated about 10% of the files. I'm pretty sure that the estimate of "over one
>>>>>terabyte" is still accurate.
>>>>>
>>>>>Since the de Koning format tends to be about 20-25% smaller than the Nalimov
>>>>>format (or at least it was with the 5-man files), you can feel free to make
>>>>>assumptions if you like....
>>>>>
>>>>>jm
>>>>
>>>>Is the 20-25% reduction referred to the normal or to the compressed files?
>>>>
>>>>Does de Koning format contain info on win, loss and draw, or only on win and
>>>>loss+draw without distinction between these last two results?
>>>>
>>>>Thanks
>>>>Guido
>>>
>>>The de Koning format is always compressed. There is no uncompressed version.
>>>
>>>The de Koning format contains win/not-win only.
>>>
>>>jm
>>
>>I need to clarify that last statement. The ReadMe file for the de Koning
>>generator program says:
>>--------------
>>The following table sheds some light on the relation between moves,
>>plies, and side to move.
>>
>>data    means wtm ...       means btm ...
>>---------------------------------------------
>>   0    (not used)          is mated
>>   1    wins in   1  ply    loses in   2  ply
>>   2    wins in   3  ply    loses in   4  ply
>> 253    wins in 505  ply    loses in 506  ply
>> 254    wins in 507+ ply    loses in 508+ ply
>> 255    draws or loses      draws or wins
>>--------------
>>
>>jm
>
>Thanks for explanations.
>It is very interesting the idea of generating TBs already compressed.
>I suppose that the 20-25% of reduction is due to the chosen format that contains
>more sequence of zeroes (from an "uncompressed" point of view), if compared with
>Nalimov's TBs.
>The main advantage of this format seems to me avoiding of 8-16 bits problem that
>will arise with 6-men TBs, paying something with the reduction in information
>contained in a single file.
>I also suppose that the algorithm used by FEG is based on the retrograde move,
>considering the relatively very short cpu time spent in generation.
>
>Ciao
>Guido

For these kinds of details, it would be best to ask Johan. I'm not fully
knowledgeable of the inner workings of FEG.

jm



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