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Subject: Re: New(?) search idea.

Author: Robert Hyatt

Date: 05:05:24 01/22/98

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On January 22, 1998 at 00:10:44, Andrew Walker wrote:

>On January 21, 1998 at 23:54:49, James Long wrote:
>
>>On January 21, 1998 at 22:27:42, Andrew Walker wrote:
>>
>>>	Here's an idea I came up with recently, it may be old news
>>>but I've never heard of it being used so here goes:
>>>
>>>	One thing I've noticed with chess programs (mainly at a fixed time per
>>>move) is that often the search will stop when they have spent ages
>>>considering the main move, or when several replys to a none best
>>>move have been examined and it looks like it may become the new best
>>>move. Generally the best thing that can happen in a search is when a new
>>>move becomes the main move and with a reasonably higher evaluation.
>>>So we would like this to happen sooner if at all possible.
>>>	The way searches normally work is that when the depth is increased, the
>>>best move will be searched first. My idea is to search
>>>all of the other moves first.
>>
>>When searching, it is important that the correct move be very close
>>to the top of the list.  This way, all other moves will be cut off
>>with minimal work.  If you searched in the opposite direction, you
>>would get absolutely no benefit from a/b cutoffs.
>>
>	Did you read the next paragraph of my post? As I have said, the
>alternate moves may be all cut off! The direction is not reverse, the
>alternates
>are searched in the same order as they would be normally.
>

How can they be cut off since the real PV move has not yet been
searched,
so we have no idea what the true score should be?


>>>	Lets say a depth 6 search has been done for white and the best move is
>>>e2-e4 with a score of +0.1. What we could do is start the depth 7 search
>>>looking at all moves except e2-e4, and make them try to beat a score of
>>>0.1+c, where c is a small positive constant such as 0.2.
>
>>>	Andrew Walker
>>>	ajw01@uow.edu.au



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