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Subject: Re: Null - Move

Author: Matthias Gemuh

Date: 01:28:09 07/04/02

Go up one level in this thread


On July 04, 2002 at 04:19:13, Christophe Drieu wrote:

>On July 03, 2002 at 17:39:25, Art Basham wrote:
>
>>Here is a good link to help anyone new here...
>>
>>http://www.seanet.com/~brucemo/topics/nullmove.htm
>>
>>I am still working on it...:-)
>
>Great, but what MakeNullMove() function do ?
>
>#define R   2
>
>int AlphaBeta(int depth, int alpha, int beta)
>{
>    if (depth == 0)
>        return Evaluate();
>    MakeNullMove();
>    val = -AlphaBeta(depth - 1 - R, -beta, -beta + 1);
>    UnmakeNullMove();
>    if (val >= beta)
>        return beta;
>    GenerateLegalMoves();
>    while (MovesLeft()) {
>        MakeNextMove();
>        val = -AlphaBeta(depth - 1, -beta, -alpha);
>        UnmakeMove();
>        if (val >= beta) // Delete these to get straight
>            return beta; // min-max instead of alpha-beta.
>        if (val > alpha)
>            alpha = val;
>    }
>    return alpha;
>}



MakeNullMove() "fixes" your data structure so that
all your routines are aware that it is other side to move.
You may have really little or almost nothing to fix.









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