Re: computer-go: Second Order Liberties

[David Fotland <fotland@xxxxxxxxxxxxxxx>]

No.  Influence is only used for group strength, not tactics.  My tactical
move sorting is mostly based on the number of new liberties gained by
a particular move.  I suppose that this has some relationship to 2nd order
liberties.

David

At 09:56 AM 5/10/2002 +0900, you wrote:
> > Many Faces does not use the concept of 2nd or higher order liberties.
> >
> > Many programs use higher-order liberties as a measure of how surrounded
> > a group is.  I prefer to use influence, measuring if there is a path to
> > another strong group.
>
> Do you use that influence idea inside tactical search as well? If so,
> did you update the influence map after each node in the search, or just
> use the influence that existed at the root node?
>
> I had good results using both 2nd and 3rd order liberties to prune and
> sort moves in tactical search. (with secondary libs allowed to be the
> primary lib of an opponent).
>
> Darren
>
> > >noticed in the GnuGo 2.6 ... that second order liberties cannot
> > >exist on an opponent first order liberty.  Is this the way everyone 
> does it?
> > >What is the reasoning behind this?
David Fotland