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Subject: Re: Looking for some information and positions

Author: Uri Blass

Date: 02:48:50 09/24/01

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On September 24, 2001 at 05:14:10, Jari Huikari wrote:

>I'd like to find information about history of computer chess:
>When alpha-beta was invented and other 'milestones'.
>
>And if I remember right I have seen here an estimation about
>how many different chess positions there are.
>
>And finally I'd like to get those strange positions where Fritz
>couldn't find easy mates: another was a zugzwang and mate wasn't
>found because of using null move

I remember this position when old versions of Fritz could not solve but
unfortunately Deep Fritz can solve it.

[D]kbK5/pp6/1P6/8/8/8/8/R7 w - - 0 1

Deep Fritz seems to be lucky here because I remember cases when it could not see
simple things because of null moves including a case when it fail to see
a simple win against Junior in comp-comp game because of null move pruning.
(Junior saw something like 10 pawns against itself when Deep Fritz saw nothing
and after Deep Fritz's mistake it was almost equality)

The comp-comp game was based on my correspondence game against the female world
champion luba kristol.

Unfortunately I am too lazy to look for this comp-comp game now.
I remember that Deep Fritz found the right move at short depthes in that game
but later it failed low every iteration without main line until Deep Fritz saw
another move.

I already posted few years ago a position when the right move leads to a
zunzwang and Fritz5(at that time) found the right move but also failed low every
iteration without solving the fail low.

It seems that chessbase does not consider that problem as important and I do not
believe that Deep Fritz is losing more than 5 elo in rating because of that
problem.

Uri



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