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Subject: Re: Conspiracy numbers.

Author: Robert Hyatt

Date: 22:22:41 07/20/99

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On July 20, 1999 at 18:10:59, José de Jesús García Ruvalcaba wrote:

>	Could somebody please explain in simple (but accurate) words the essentials of
>conspiracy numbers search?
>	I know I can read the research papers from the Zugzwang team, but first I need
>something less dense.
>José.


The basic idea is to detect deep forcing lines.  The idea is this.  If you
reach a position P in the tree, and from that position you search a set of
moves leading to new positions...  how many of those successor moves actually
affect the current score?

IE if the score is a result of only one move, then we consider this a forcing
position where there is no real chance to vary...  The term 'conspiracy' comes
from the idea of "how many positions below this position have to 'conspire'
together to change the score at this position?"  If changing the score of one
move changes this position, it is forcing.  If changing the score of many moves
doesn't affect this one, it is a 'quiet' position...

There are other details, but that is the gist of why it might be useful...
Because at every node where the conspiracy number is low (only a few scores
have to change to change this position) we can search deeper since this is a
forcing position.  In positions where it takes a lot of changes below this
node to change the score at this node, we don't extend because it is not a
forcing position.

When you think about it, it is a form of singular extension, a form of check
extension, a form of one-reply extension, etc...



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