RE: computer-go: Pattern matching

[David Fotland <fotland@xxxxxxxxxxxxxxx>]

Often several patterns suggest the same move, perhaps 3 to 8.  And a
symmetrical pattern can suggest the same move twice.

In a typical middle game position, the pattern database will suggest
perhaps 50 to 100 moves.  If you have Many Faces, you can turn on
"Move Suggestions" and select every type of suggestions.  All of these
moves are suggested from pattern matches.

Each move suggested by a pattern has a value associated with it in the
pattern library.  Additional values are calculated depending on the
type of pattern by some C code.  For example, if the pattern is
suggesting a running move, additional value is added depending on
the size and strength of the group that is doing the running.  I use
these values to sort the moves and evaluate as many as I have time for,
perhaps 10 or 15, but sometimes as few as 3 to 5.

David


At 10:02 AM 11/4/99 -0800, you wrote:
>
>Choosing patterns is easy.  I look at games the program played, and when
>it
>makes a bad move because a pattern is missing, I add it.  Since patterns
>are
>suggesting moves, not evaluating them, there is no issue with having too
>many 
>patterns, or multiple similar patterns that suggest the same move.  All
>moves
>are suggested for a reason, which leads to a natural partitioning of
>patterns
>
>* One question:
>	Suppose for a board status, many (say 50 or 200) patterns are
>matched, do you prioritize the patterns before you do the evaluation or
>you evaluate every one of them?
>
>* Thanks, David. You are really a open-minded person to share all of
>your thinkings with us.
>
>-- Mousheng
>
>