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Subject: Re: Some explanations about SmarThink

Author: Sergei S. Markoff

Date: 03:06:31 06/06/03

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>the problem with the trajectories seems to be that not many people seem to
>understand what botvinnik MEANT with his trajectories. maybe
>you can tell us what YOU understood :-))

((:

Botvinnik was a person with a very "wide" mind (:
I can show you some of ideas that can be used to construct working method.
For example, you can found that some chess operations includes the moving some
piece from one board region to another. It can be easily found for example in
several endgames.

Null move doing a very bad thing in some positions. It "cuts" some of this
trajectories. For example to finish attack on opponent king we must move rook
from f1 to g3. This operation includes, for exapmle, 3 plies: f1-e1, e1-e3,
e3-g3. We need to search with Depth = 6 plies to found this operation. If we has
one or tho pawns less before performing this operation, null-move can found that
when opponent not moving we, anyway, can't do something good in 4 plies (R=2)
and it causes cut-off.

The other problem is endgame. Is some pawn endgames we must move our king from,
say, h1 to e7. But our search is "blind". 12-ply search discovers right
trajectory, but it also discovers a lot of really stupid king movements. In some
cases it's a good idea to extend some trajectories if we can see a goal - some
pawn rams or something else. In SmarThink I tried to extend some nodes in which
we see that previous king movement is a shape with no self-intersections and
without moving to squares that can be reached by king early. This method also
need some special cut-offs to stop cathastropic tree expanding.

I'm working to improve all of this methods. And I'm interesting in your ideas (;



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