[rec.games.go] Amiga Go

poirier@dg-rtp.dg.com (Charles Poirier) (05/04/90)

In article <4120@infmx.UUCP> giao@infmx.UUCP (Giao Tien Vu) writes:
>The GNU Go version that I worked on a while ago was abandoned due to:
>
>	a) poor computer player (as a beginner, I only lost one game during
>	   playtesting).  The computer made a lot of bad moves.

I've beta tested a Gnu Go Amiga port lately, and took a peek at the source
code, and the above is an understatement.  A lot of those "bad moves" are,
in fact, *random* moves.  It's gen_move algorithm is basically 1) Can it
capture immediately or threaten capture, 2) Can it avoid immediate capture,
3) Is there a stone pattern (out of about 20 canned patterns plus their
rotations and reflections) for which it has a canned next move, 4) Pick
someplace at random having at least two liberties and not too close to an
edge, 5) If after 400 attempted picks it can't find a qualifying random move,
pass.

Needless to say, the last two rules make playing the endgame to conclusion
really infuriating, at 40 to 75 seconds per move.  I had to subdivide my
entire vast territory into two-point cells to get Gnu Go to finally give up
the ghost.  Rule 3 is an interesting idea, but, I think, of inadequate power
or generality to play good Go, regardless of pattern tuning.  I believe it is
doomed to run afoul of a common trap of rule-based design, by which it is easy
enough to wire in a few sound features but terribly difficult to cover all
bases.  There is no provision for proscriptive patterns, saying "Don't play
here!"  Gnu Go's patterns have no global sense; it was rather eager to play
move after move making redundant eyes inside its own territory.  The rules
have no sense of what makes for a live group, nor of how much area is needed
to make a live group.  They have no concept of influence.  There are other
problems.  I'm sorry to say it, but I think Gnu Go deserves to be abandoned.

	Cheers,
	Charles Poirier   poirier@dg-rtp.dg.com