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Subject: Re: Can opponent's thinking time be a search/eval parameter?

Author: Uri Blass

Date: 00:50:44 10/18/02

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On October 18, 2002 at 03:32:00, Uri Blass wrote:

>On October 17, 2002 at 23:48:27, Robert Hyatt wrote:
>
>>On October 17, 2002 at 19:57:41, Uri Blass wrote:
>>
>>>On October 17, 2002 at 18:12:02, Robert Hyatt wrote:
>>>
>>>>On October 17, 2002 at 16:34:08, Murray wrote:
>>>>
>>>>>On October 17, 2002 at 10:07:41, ujecrh wrote:
>>>>>
>>>>>>(snip)
>>>>>>We can track opponent's thinking time and, without trying to match it, add some
>>>>>>time or search extensions when an unusual delay has occured.
>>>>>>
>>>>>
>>>>>But humans also ponder when the computer is thinking. It could be argued that if
>>>>>the human is having to spend a long time thinking in a difficult position, the
>>>>>computer should play just as quickly or quicker than normal, to reduce the
>>>>>human's chance of seeing through the complications.
>>>>>
>>>>>Murray Cash
>>>>
>>>>
>>>>If the computer had any _idea_ about what makes up a complex/hard-to-analyze
>>>>position,
>>>>this would be a good plan.  But it doesn't have a clue about whether the
>>>>opponent has an
>>>>easy or difficult position to play, and trying to play games with time usage
>>>>will more often
>>>>than not blow up in your face....
>>>
>>>The computer may ponder about all the possible moves but use different time for
>>>different moves(I remember that I read that this idea is used by aristarch).
>>>
>>>If based on the scores it can see that there is a forced move it can give it
>>>almost all of the time but if it see 5 moves with almost the same score it can
>>>continue to analyze them and use almost 1/5 of the time for everyone of them.
>>
>>This idea is simply no good.  I have explained why a dozen times or two, over
>>the past 10 years...  It doesn't work now.  It didn't work 20 years ago.  It
>>won't
>>work 20 years from now either.
>>
>>The _best_ way to ponder is to pick the best move and go with it, unless the
>>program
>>is so bad it can't predict right even 50% of the time, which is very low...
>
>I think that the best way to ponder is not so simple
>I do not try today to use it and movei ponder only on the expected move
>or wait in case that it finished to ponder.
>
>It is certainly better than using the same time for all moves
>but if you ponder more time on the better moves than I believe that
>pondering on all the moves may be better.
>
>You should start by pondering most of the time on the expected move but if you
>fail high on the search after the expected move or if the difference in
>evaluation relative to other moves is small then you can increase the time for
>the other moves.
>
>Small difference means less than 0.1 pawn and
>if the difference in evaluation is 0.3 pawns you still may
>use 70-80% of your time for the expected move and if the difference
>is more than 1 pawn you may use even more than 90% of your time for the expected
>move.
>
>Uri

I can add that I have no experience in threads but I guess that
it is possible to have a thread for every legal move of the opponent
and to update every second the percentage of time
that is going to be used for every thread.

Uri



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