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Subject: Re: The Scalable Search Test

Author: blass uri

Date: 23:12:32 06/19/00

Go up one level in this thread


On June 19, 2000 at 19:02:51, Ed Schröder wrote:

>On June 19, 2000 at 13:22:31, blass uri wrote:
>
>>On June 19, 2000 at 11:47:12, Ed Schröder wrote:
>>
>>>On June 19, 2000 at 04:45:33, blass uri wrote:
>>>
>>>>On June 19, 2000 at 03:03:49, Ed Schröder wrote:
>>>>
>>>>>On June 18, 2000 at 19:46:03, Dave Gomboc wrote:
>>>>>
>>>>>>On June 18, 2000 at 18:21:01, Ed Schröder wrote:
>>>>>>
>>>>>>>On June 18, 2000 at 16:34:16, blass uri wrote:
>>>>>>>
>>>>>>>>On June 18, 2000 at 12:00:08, Ed Schröder wrote:
>>>>>>>>
>>>>>>>>>On June 18, 2000 at 10:36:40, Gian-Carlo Pascutto wrote:
>>>>>>>>>
>>>>>>>>>>On June 18, 2000 at 10:17:08, Ed Schröder wrote:
>>>>>>>>>>
>>>>>>>>>>>According Rebel it is a mate in 10.
>>>>>>>>>>>
>>>>>>>>>>>Ed
>>>>>>>>>>>
>>>>>>>>>>>00:00  07.00  0.81  1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 Ke8 4.Rh8+ Kd7 5.Qf5+ Kc7
>>>>>>>>>>>00:01  08.00  2.37  1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 Ke8 4.Qf5 Kd8 5.Qxf7 Kc8
>>>>>>>>>>>6.Qxe7
>>>>>>>>>>>00:03  09.00  2.47  1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 Ke8 4.Qf5 Kd8+ 5.Qxf7 Kc7
>>>>>>>>>>>6.Qxe7+ Kc8
>>>>>>>>>>>00:43  10.00  11.74  1.Rxh5 gxh5 2.Rxh5 Kf8 3.Rxh7 e6 4.Bf6 Ke8 5.dxe6 Qxc4+
>>>>>>>>>>>6.Qxc4
>>>>>>>>>>>02:35  11.00  Mate in 10 moves 1.Rxh5 Kf8 Rxh7 2.Ke8 Rxf7 3.Qxc4 Qxc4 4.g5 Rhh7
>>>>>>>>>>>5.b5 Rxe7+ 6.Kd8
>>>>>>>>>>
>>>>>>>>>>I find it interesting to notice that even Rebel has some trouble with this,
>>>>>>>>>>taking more than 10 times as much time to resolve the 10th ply.
>>>>>>>>>
>>>>>>>>>That's pretty normal whith such big score differences (2.47 -> 11.74) as
>>>>>>>>>search is confrontated with big score fluctuations which causes move
>>>>>>>>>ordering to collapse. I wouldn't bother too much about it, it's quite
>>>>>>>>>normal.
>>>>>>>>
>>>>>>>>Not for all programs.
>>>>>>>
>>>>>>>Of course.
>>>>>>>
>>>>>>>>Chessmaster6000(ss=10) can see a forced mate in only 4 seconds and does not have
>>>>>>>>a big branching factor
>>>>>>>
>>>>>>>Sure. Maybe not in this position.
>>>>>>>
>>>>>>>>This is normal for chessmaster to see mates clearly faster than other programs
>>>>>>>>and I think that this is because the other programs do some mistakes in their
>>>>>>>>search rules.
>>>>>>>
>>>>>>>Nope. Johan has special (mate) stuff in his search no program has.
>>>>>>>
>>>>>>>Ed
>>>>>>
>>>>>>Just curious... why don't you add it to Rebel too? :-)
>>>>>
>>>>>a) because I don't know "exactly" what it is;
>>>>>b) too much emphasis on mates loses too much elo points in games.
>>>>>
>>>>>Ed
>>>>
>>>>I think reason a is the right reason because I do not think that chessmaster
>>>>loses too much elo points in games(chessmaster6000 is one of the top programs
>>>>and is only one point behind Fritz5.32 in the ssdf list inspite of having no
>>>>learning function and having an older engine)
>>>>
>>>>I believe that having special mate stuff is productive for chess programs if you
>>>>do it in the right way.
>>>
>>>The right way? Now tell me what that is... You might ask yourself the
>>>question if such a thing exist in computer chess.
>>>
>>>Finding deep mates requires extensions. Extensions mean a higher branch
>>>factor. A higher branch factor means a lower search depth. A lower search
>>>depth means a lower elo.
>>
>>The right way is to do it almost without a lower search depth.
>>In order to do it you need to do the extensions only in the right places so when
>>there is no mate danger you will not have lower search depth.
>
>The right way to do it ussue again. Ever tried to do it yourself?
>If not try it yourself and let's talk again 4-5 years later.

I did not say that it is easy to do it.
>
>
>>You can also decide to have a time limit for searching with the extensions(for
>>example 1/10 of the time per move).
>
>Tried it?

No
I did not say it is easy to do it but only that I believe that it is possible.
I guess that there are more important things for you to do in the near future.

>
>It's no good. In fact it is a non working idea. When you for instance
>find something interesting in the first part with many extensions you
>will lose it as soon as you go back to normal search. Now that looks
>real silly for a chess program that after (say) ply 5 finds a nice
>tactical shot and then fails low on the 6th ply and then finds the
>combination back on ply 9 or 10.

This was not what I meant.
I did not think to forget about what you found.
Of course if you find something intersting(a fail high or a fail low) there is
no reason to forget it and you can choose between only avoid doing extensions in
nodes that you did not search and if there is a problem with doing it to
continue with the extensions.

If you do not find something interesting you can forget about the extensions.

I think that it may be better in a correpondence game to use chessmaster for
1/10 of the time when I suspect that there may be a mate danger and if
chessmaster does not see something interesting to use another program for 9/10
of the time.

I believe that it is better than to use only the other program.
If I am right then the other program could be better if it knew to do the same

Uri



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