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Subject: Re: If you like to solve easy mate...

Author: leonid

Date: 13:02:35 02/09/01

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On February 08, 2001 at 19:07:22, Pete Galati wrote:

>On February 08, 2001 at 17:08:36, leonid wrote:
>
>>On February 08, 2001 at 11:42:40, Pete Galati wrote:
>>
>>>On February 08, 2001 at 11:31:35, leonid wrote:
>>>
>>>>On February 08, 2001 at 10:45:07, Heiner Marxen wrote:
>>>>
>>>>>On February 08, 2001 at 10:09:29, leonid wrote:
>>>>>
>>>>>>On February 08, 2001 at 09:49:16, Pete Galati wrote:
>>>>>>
>>>>>>>On February 08, 2001 at 08:21:44, leonid wrote:
>>>>>>>
>>>>>>>>Hi!
>>>>>>>>
>>>>>>>>If you like to solve easy (not deep) forced mate position, here is the one.
>>>>>>>>
>>>>>>>>[D]Nb1rkrNb/1n1pqp1b/n2qqq1n/1NNNNNNn/2BNNB2/1R2Q1R1/8/2K5 w - -
>>>>>>>>
>>>>>>>>Please, indicate your result.
>>>>>>>>
>>>>>>>>Thanks,
>>>>>>>>Leonid.
>>>>>>>
>>>>>>>Crafty found the mate in 8 a little bit earlier but it had it's hashtables all
>>>>>>>filled up, and I can't operate it at up to 96mb hashtables on my computer, so
>>>>>>>I'm stuck with 48 at the moment.  I never get around to mentioning, it's a
>>>>>>>700mhz Celeron.
>>>>>>>
>>>>>>>Pete
>>>>>>>
>>>>>>>5 piece tablebase files found
>>>>>>>1836kb of RAM used for TB indices and decompression tables
>>>>>>>EGTB cache memory = 3M bytes.
>>>>>>>hash table memory = 48M bytes.
>>>>>>>pawn hash table memory = 5M bytes.
>>>>>>
>>>>>>Simply can't detain my curiosity, what is the "pawn hash table"? Special hash
>>>>>>table just for pawns?
>>>>>
>>>>>Yes, for that part of the eval which is based only on the location of
>>>>>all the pawns (pawn structure).
>>>>>
>>>>>
>>>>>>Thanks for detailed decription! Sometime, some very interesting moments come to
>>>>>>light.
>>>>>>
>>>>>>My program found at the same depth mate but I not looked by brute force. It
>>>>>>could be that somebody will come with shorter mate.
>>>>>>
>>>>>>Leonid.
>>>>>
>>>>>I doubt it.  Chest says "no mate in 7" after 68.4 minutes.
>>>>>You all found the shortest mate:  Congratulations!
>>>>
>>>>Thanks, but I doubt very much that my program will search 7 moves in one hour.
>>>>It had awful branching factor and in 5 moves already went to 10 min. Selective
>>>>search make me feel this by solving position by easiest level (8 moves deep)in
>>>>18 sec. Usually it should be only split of one second for 8 moves, for that
>>>>search level.
>>>>
>>>>Brute force search:
>>>>
>>>>3 moves - 0.38 sec
>>>>4 moves - 22.3 sec
>>>>5 moves - 9 min 52 sec
>>>>
>>>>Leonid.
>>>
>>>Here's a paragraph from Bob's Crafty doc file related to the pawn hashtables:
>>>
>>>"23.   hash=x  and hashp=x  These commands are used to adjust
>>>the size of the hash tables in Crafty.   hash  modifies  the
>>>size of the transposition/refutation table, while hashp mod-
>>>ifies the size of the pawn structure/king safety hash table.
>>>The  sizes  may be entered as one of the following two types
>>>of values: nnnK where nnn is an integer indicating how  many
>>>Kbytes Crafty should use for this hash table; nnnM where nnn
>>>is an integer indicating how many Mbytes Crafty should  use."
>>>
>>>Pete
>>
>>Thanks, Pete!
>>
>>Now I see that Crafty code should be completely different from everything that I
>>have in my program. Difference is everywhere! The first impression I had when
>>I looked into Kerrigan description and he said me that its code is "like usual".
>>
>>Leonid.
>
>I'm not sure what Tom would have meant by "like usual".  I suppose if you look
>at Crafty's individual functions, you might not see too many UNusual things, but

When I said "like usual" it is more in the sense of general construction of the
program. Differences in different programs are more based on individual
preferences than on basic differences. Individual preferences - null move or
selective search... New in each program is mainly some new special way that
became "usual" as soon as given program used it for before everybody else.

>when you look at Crafty as a whole, I would call it a text book in Chess and C
>programming.
>
>It is extensive, but it's not too difficult to find your way around with
>something like grep.  I haven't looked at the Crafty code for a while, but it's
>well worth a tour if you have the time to do it.


This is what I want to do for a long time and it could be that now it is even
too late. All basic part of my program was done. I must only find the time and
come to it in order of finishing my program. This time I must to have a patience
of working on second part (first is mate solver) as much as I worked in the
beginning. Successful program it is not only that one that you started with big
spirit but that you ended on the same note as well.

Leonid.


>Pete



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