Author: Bruce Moreland
Date: 09:26:16 03/24/99
Go up one level in this thread
On March 24, 1999 at 08:45:23, Robert Hyatt wrote:
>Quiesce is a simple search that looks like this (details omitted but basic
>idea is present):
>
> int Quiesce(alpha,beta,wtm) {
> alpha=Evaluate(etc);
> if (alpha > beta) return(beta);
You mean alpha >= beta, but this is goofy if Evaluate returns a value < alpha,
isn't it? This will make your window wider.
bruce
> while(more_captures) {
> MakeNextCapture();
> value=-Quiesce(-beta,-alpha,wtm^1);
> if (value > alpha) {
> if (value >= beta) return(beta);
> alpha=value;
> }
> }
> return(alpha);
> }
>
>
>the difference between Quiesce and Search is that Quiesce sets the lower bound
>to the current positional evaluation + material. Because we allow the current
>side to 'stand pat' and not play any move (capture only) if he doesn't want to.
>
>Search() doesn't allow one side to 'not move' as that is illegal. But here we
>use it to 'stop' the sequence of captures and exit, or else we can make a
>capture that helps our score, but then the opponent gets to decide whether he
>wants to 'stand pat' or make a capture in response.
>
>Hope that helps..
>
>If something isn't clear, feel free to ask, as there could easily be a typo in
>the above...
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