Author: Antonio Dieguez
Date: 08:24:21 01/06/04
Go up one level in this thread
On January 06, 2004 at 06:36:56, Vincent Diepeveen wrote:
>On January 05, 2004 at 22:38:45, Antonio Dieguez wrote:
>
>>On January 05, 2004 at 19:48:25, Bas Hamstra wrote:
>>
>>>>>Here is what I tried (idea from Bruce I believe):
>>>>>
>>>>>Before you search all moves (after nullmove) you search all moves (unsorted)
>>>>>with D-R
>>>>
>>>> Good point I had missed :)
>>>> I was doing an expensive D search with (Alpha-Margin,Alpha-Margin+1) and if
>>>>only one move failed high, search it again with (Alpha,Beta) extended 1 ply.
>>>>
>>>>>and check if there is one and only one move with a score above alpha
>>>>>*and* above Alpha-Margin.
>>>>
>>>> So if I get it right, you search all moves with D-R and a null window around
>>>>Alpha-Margin. If only one move fails high, then search it again with D-R and a
>>>>null window around Alpha. If it fails high again, then that move is extended.
>>>
>>>It did not do this, but your idea might be better. I did one single pass with
>>>window(Alpha-M, Alpha) and simply counted the results.
>>
>>hi
>>
>>I don't know if you did it or if it makes big difference, but now that i think
>>of it, when searching with a window that includes ranges that are worth the same
>>(areas XYZ, like Alpha-M+1 to Alpha-1 in your window above) there is an
>>optimization like this, at the top of search. Don't ask me what is best.
>>
>>if (alpha is in an area XYZ)
>>{
>> alpha = higher value in area XYZ;
>> if (alpha>=beta)
>> { return beta; }
>>}
>>
>>if (beta is in an area XYZ)
>>{
>> beta = lower value in area XYZ;
>>}
>
>This is only possible when your program does not use a transpositiontable.
>
>Vincent
oops, right.. i didn't think of it. It can't be so pretty.
i wonder if it is still an optimization if the saving in hash is fixed here, or
then because of the less info saved it is the contrary.., or doesn't make a
diff. and the implementation is ugly so better quit it, who knows, not me
the always very usefull
antonio d.
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