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Subject: Re: How much time does your program need to see the draw?

Author: Uri Blass

Date: 06:34:51 06/22/02

Go up one level in this thread


On June 22, 2002 at 07:51:03, Sune Fischer wrote:

>On June 22, 2002 at 06:56:11, Uri Blass wrote:
>
>>On June 21, 2002 at 12:28:49, Christophe Theron wrote:
>>
>>>On June 21, 2002 at 06:53:41, Uri Blass wrote:
>>>
>>>>On June 21, 2002 at 04:57:44, Russell Reagan wrote:
>>>>
>>>>>On June 21, 2002 at 04:38:04, Uri Blass wrote:
>>>>>
>>>>>>How much time does your program need to see that it is a draw?
>>>>>
>>>>>At least a few more weeks :)
>>>>>
>>>>>Russell
>>>>
>>>>It is an easy draw for the following reasons;
>>>>
>>>>
>>>>1)White need always to move the knight by Nb3 N.. Nb3 N.. Nb3 N.. when the
>>>>knight is never captured(the knight is never captured in b3 and we need to prove
>>>>that the knight has a safe black square to go in order to prove that it is a
>>>>draw).
>>>>
>>>>2)The black king cannot control a1 so the black bishop needs to be in the long
>>>>diagnol in order to prevent a1 from the knight.
>>>>
>>>>3)The black bishop in the long diagnol can not control a5 so the black king
>>>>needs to control that square.
>>>>
>>>>4)3 means that the black king cannot control c1 and d2 so the black bishop needs
>>>>to control these squares but the black bishop must be in b2 in order to control
>>>>both a1 and c1 and it does not control d2 from that square.
>>>>
>>>>I believe that even programmers with rating of 1500 can find that it is a draw
>>>>and I wonder if one of them was smart enough to write the relevant code to
>>>>explain it to the computer.
>>>>
>>>>Uri
>>>
>>>
>>>
>>>The question is: will it make the program stronger?
>>>
>>>I can easily see how it can make a program weaker by slowing it down, and I
>>>seriously doubt it will increase the program's rating by a single elo point.
>>
>>I can see how it can make the program better.
>>
>>If you have a function that calculates it only at the first plies and continue
>>to claculate it only if it finds that the knowledge is relevant then the program
>>may be only 0.1% slower in most of the positions when it may see the draw and
>>avoid a mistake in some cases.
>>
>>You can still say that there are things that are more important to do but I
>>believe that every knowledge can do programs stronger.
>>
>>Uri
>
>I think that if this should be have any effect on strength (against humans) it
>should be detected at the leaf nodes, so we have a few plies to avoid it.

I think that the leaf nodes of 3 ply or 4 ply search may be enough in part of
the cases.

Not in every case but in significant part of the cases when similiar problems
happen and when the hardware get faster the programs may search even deeper
because I suggest to use 0.1% of the time for these problems and I do not
suggest to use fixed depth(it may be even better to use even 1% of the time but
not 50% of the time).

>There is no doubt the GM will spot this draw a long time before its on the board
>and will play for if he is in trouble.

Even in this case it is not clear that he can give the program a long forced
line for the draw so detecting the draw few plies before it happens may be
enough.

Note that I do not use these ideas today in movei because there are more
important things to do and I do not work a lot about movei.

Uri



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