Author: Robert Hyatt
Date: 16:55:58 03/24/99
Go up one level in this thread
On March 24, 1999 at 12:26:16, Bruce Moreland wrote:
>
>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
>
yes... I just tried to make the code short.
it really looks like this:
value=Evaluate();
if (value > alpha) {
if (value > beta) return(beta);
alpha=value;
}
etc...
Bob
>> 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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