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Subject: Re: How many possible moves in one position?

Author: Robert Hyatt

Date: 17:26:34 12/07/97

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On December 07, 1997 at 18:50:01, Jari Huikari wrote:

>On December 07, 1997 at 18:16:17, Enrique Irazoqui wrote:
>
>>On December 07, 1997 at 17:20:34, Jari Huikari wrote:
>
>>>Does Hiarcs allow this position? Maybe it noticed that there
>>>were this trouble to find the last move for black in your
>>>first position.
>
>>No. Hiarcs 6, Mchess 7, CST and CM5K don't accept it. Genius 5, Rebel 9,
>>Shredder 1 and Fritz 5 do, but only Fritz gives the number of legal
>>moves.
>
>This sounds interesting. Do the programs have some maximum number of
>legal moves? I supposed that they probably don't.
>
>What about Crafty? Has it some maximum 'much' bigger than 200 or
>do it use memory dynamically?
>
>					Jari


there are two issues in crafty.  the move list is dynamic in size,
because
I have an array moves[N], plus a pointer for each ply that points to the
beginning of the move list.  So a move list can have any number of
moves.

Another problem, however, is an array I use to sort the moves at the
root
of the tree.  This is dimensioned for [256] as I don't believe it is
possible to approach this number, although exceeding 200 happened to me
years ago (not in a real game however, just in some oddball problem
position
of Harry's...)

So for crafty, up to 256 moves will work perfectly...  anything bigger
will
require increasing the size of this array...



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