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Subject: Re: For Dr. Robert Hyatt

Author: Robert Hyatt

Date: 20:04:21 12/30/03

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On December 30, 2003 at 22:27:24, Ed Trice wrote:

>Hello again Dr. Hyatt,
>
>>
>>That is the very reason that I make the source public.  And yes, 80 bit words
>>won't be a serious problem..  Remember that the _original_ 64 bit program,
>>chess 4.0, ran on a 60 bit computer, so it had to use two words to get 64
>>anyway.  You will just use 3 on 32 bit machines, or 2 on 64 bit machines.
>>
>
>Thank you very much! I must say, I am *very* impressed with the concept of the
>static exchange evaluator. It is like a tree-search without all of the overhead
>calling of the move generator!

Idea came from Dennis Cooper and Ed Kozdrowicki of the old COKO program.  I
knew them pretty well back in the early 1970's and Ed gave me the idea and
the original SEE code I started using back then...  The idea has stuck around
for 30+ years now as Coko used this in 1970 when I met the two authors at the
first ACM event.

>
>
>>
>>Sounds like a fun project...   Keep us posted here...
>
>The first step will be using C++ operator overloading for the bitwise routines
>for the SHIFT, AND, OR functions, etc.
>
>As for the evaluation function for the values of the new pieces, I have already
>come up with a derivation based on Taylor's work (1876).
>
>You can see the detailed explanation of it here:
>
>http://www.GothicChess.org/piece_values.html
>
>Taylor derived equations for "safely checking a king" to roughly come up with
>values for the pieces. On a 10x8 board, all of the pieces lose strength. The
>Knight loses the most (-16.67%) and the Rook the least (-5.50%)

I could see why.  Knight is already stretched pretty thin on 8x8 in some
endgames.

>
>Thanks again for allowing me to use Crafty as a baseline.
>
>When I have a test version ready, I will let you know.
>
>--Ed



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