Author: Sune Fischer
Date: 07:46:07 06/22/02
Go up one level in this thread
On June 22, 2002 at 09:34:51, Uri Blass wrote:
>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
I think the problems lies in how do such an evaluation,
are you going to write:
if (white has 1 bishop &&
black has 1 knight &&
white has 2 connected pawns &&
black has his king and knight under the pawns &&
white has a bishop of wrong color && // subroutine call needed
black can't be forced away && // subroutine call needed
black has enough squares to not be in zugzwang) // subroutine call needed
return contemptfactor;
just to solve 1 specific case?
What if the pawns are not connected, what if....
There could be cases where this is not even draw.
It is not something I plan to implement in the near future, that's for sure ;)
-S.
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