Author: Dan Honeycutt
Date: 17:29:34 03/13/04
Go up one level in this thread
On March 13, 2004 at 17:47:06, Uri Blass wrote:
>On March 13, 2004 at 17:40:06, Russell Reagan wrote:
>
>>On March 13, 2004 at 17:32:49, Uri Blass wrote:
>>
>>>I think that you do not understand my idea
>>>
>>>I suggest to do exactly the same things in the same order but to check for
>>>repetition or hash cut off before calling search and not after calling search.
>>
>>Is this what you are wanting to do? Let's say the search normally looks like
>>this:
>>
>>int AlphaBeta(int depth, int alpha, int beta)
>>{
>> if (depth == 0)
>> return Evaluate();
>>
>> TryRepetition(); // <--------
>> TryHashTable(); // <--------
>> TryNullMove(); // <--------
>>
>> GenerateLegalMoves();
>> while (MovesLeft()) {
>> MakeNextMove();
>> val = -AlphaBeta(depth - 1, -beta, -alpha);
>> UnmakeMove();
>> if (val >= beta)
>> return beta;
>> if (val > alpha)
>> alpha = val;
>> }
>> return alpha;
>>}
>>
>>You are wanting to do this?
>>
>>int AlphaBeta(int depth, int alpha, int beta)
>>{
>> if (depth == 0)
>> return Evaluate();
>>
>> GenerateLegalMoves();
>> while (MovesLeft()) {
>> MakeNextMove();
>>
>> TryRepetition(); // <--------
>> TryHashTable(); // <--------
>> TryNullMove(); // <--------
>>
>> val = -AlphaBeta(depth - 1, -beta, -alpha);
>> UnmakeMove();
>> if (val >= beta)
>> return beta;
>> if (val > alpha)
>> alpha = val;
>> }
>> return alpha;
>>}
>>
>>Basically to avoid the extra function call?
>
>Yes
>Except that I thought to trynullmove in the beginning of the search.
>
>It may be better to try null move also not in the beginning of the search
>because it is possible that null move does not have search call and only call
>qsearch.
>
>Uri
I don't think you want TryNullMove() where shown in the second example. After
MakeNextMove() you have a new position which could be a repetition or be in the
hash table. but TryNullMove() should come before GenerateLegalMoves().
Dan H.
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