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Subject: Re: How do you represent chess boards in your chess programms

Author: Robert Hyatt

Date: 18:45:30 09/26/99

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On September 26, 1999 at 16:58:03, Alessandro Damiani wrote:

>On September 26, 1999 at 16:22:22, Robert Hyatt wrote:
>
>>On September 26, 1999 at 14:08:00, Alessandro Damiani wrote:
>>
>>>
>>>Yes, as it is always the case one has to know all properties of the objects one
>>>handles with.
>>>
>>>I detect passed pawns incrementally, with a few ANDs. This could only be
>>>possible because of BitBoards.
>>>
>>>Alessandro
>>>
>>
>>
>>I don't do anything incrementally at present...  that is an efficiency
>>issue. I have ignored incremental eval because it locks you into a box, since
>>the code is mixed between Evaluate() and the Make()/UnMake() code.  I found
>>that in Cray Blitz, (which did a lot of incremental work) I found myself stuck
>>in a box that served as a limiting factor. At present I am far more interested
>>in what is good and what is bad in the evaluation code.  Once I am satisfied
>>with something, I will go back and look at it from an efficiency point of view.
>>Right now I am looking at it with a "design with change in mind" sort of
>>software engineering approach..  make it easy to add things whether they are
>>efficient or not.  If they are good, then make them efficient.  IE it is very
>>possible that a lot of my pawn stuff could be done incrementally and would maybe
>>faster.  But once I go to that much work, I would likely tend to keep using that
>>code even if something better came long idea-wise.  I'm not ready to commit to
>>most of what I do, until I am sure it works as I want..
>
>You are perfectly right. I do incremental work to get information the leaf
>evaluation needs. For instance, passed pawns are detected incrementally but
>evaluated at the leaf nodes. Since passed pawns are "standard" knowledge I have
>done it this way.
>
>Alessandro


And then you discover 'candidate passed pawns' and the circle starts over.

:)



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