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Subject: Re: Pondering ("think on opponent's time")

Author: Uri Blass

Date: 02:40:42 11/13/02

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On November 13, 2002 at 05:07:48, Sune Fischer wrote:

>On November 13, 2002 at 01:10:23, Uri Blass wrote:
>
>>The point is that it may be better to use average of only 80% of the time for
>>the expected move and the rest of the time for other moves when you do not use
>>the same time for all of the other moves.
>>
>>These 80% may be 90% in cases that the move that you predict is played and less
>>than 80% in cases that the move that you predict is not played.
>>
>>Having less risks in trying to predict the opponent's move is also important
>>and if I have to choose between using 60% of my time for the played move in
>>every case(option that I do not have) and using 100% of my time for the
>>predicted move in 60% of the cases I prefer the first option.
>>
>>I cannot get the first option but I may get something closer to it.
>>
>>Uri
>
>I understand your point.
>I think it would be better to do it like this: You spend 100% on the pridicted
>move until you start suspecting this wasn't the best move, eg. it fails high.
>
>Now you go back and do a shallow search on all the possible moves, not including
>the move you just tried of course. This shallow search will be more efficient
>than the threads because it can use alpha-beta all the way.
>After a 5-6 plies search (or however long you want to spend finding the
>candidate move) you have a move to ponder and you start pondering that.
>
>If the best move is the best only for a very deep reason, and it wasn't already
>the pridicted move, then you won't be able to find it unless you do a long
>search like your opponent. So it seems this will always be a ponder miss no
>matter what. We can't make a perfect scheme anyway, so we must be willing to
>accept a miss now and then and not go out of our way to fix all the exceptions.
>
>You probably wanted to use the information from the threaded moves search to
>help seeing when the pridicted move was wrong, but I don't see what value lots
>of 2-4 ply searches have you when the pridicted move isn't failing high?
>
>-S.

I can learn from a lot of 2-4 ply search about the logical moves.
In an extreme case there is only one logical move except the move that I ponder
so I can continue to search it and give it almost 10% of the time.

Suppose that I see the following

after expected move:
score -0.2 at depth 1-10

after second best move
score 0.1 at depth 1,2
score 0 at depth 3,4
score -0.1 at depth 5,6
score -0.19 at depth 7.

It is still not the best move but I can suspect that it is going to be the best
move because of the behaviour of the sequence of the scores

Uri



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