Re: computer-go: unmake move?

[Tristan Cazenave <cazenave@xxxxxxxxxxxxxxxxx>]

Darren Cook wrote:

> >>In your paper you give an example of reading to catch
> >>a 4 stone group in figure 4.  You say that it takes
> >>787 nodes with abstract proof search and 44K nodes
> >>with heuristic search.  I assume the tactical
> >>problem is White to move and capture 4 stones.
> >>
> >>Many Faces's heuristic search only looks at 27 nodes
> >>to solve this one.  So you still have lots of room for
> >>improvement :)  The heuristic tactical move generator
> >>only selects one non-optimal move in this search for
> >>white, and gets the correct move on the second try.
> >
> >By the way, I do not understand how you get 27 nodes,
>
> I was waiting for Tristans reply to this. The reply I was expecting was
> that Tristans program searches for all possible moves that work, while Many
> Faces stops as soon as it finds one move that works. Is that not the case
> here?

That's also true, and I forgot to mention it in my reply. I search

3 plies deeper than the shortest solution depth so as to find

other moves that may work. The result I gave (38 nodes) is with this option

switched off, and the ordering of moves in the quiescence search is done

with playing the move that would give the string to capture the most

liberties.

--
Tristan Cazenave
Universite Paris 8, Departement Informatique, Labo IA
2, rue de la Liberte 93526 Saint-Denis Cedex - France
http://www.ai.univ-paris8.fr/~cazenave/