Re: computer-go: 5x5 Go is solved

[Erik van der Werf <E.vanderWerf@xxxxxxxxxxxxx>]

Markus Enzenberger wrote:
> 
> On Sunday 20 October 2002 10:27, Erik van der Werf wrote:
> > Yesterday my program solved 5x5 Go starting with the first move in the
> > centre. As was expected it is a win for the first player with 25
> 
> did you allow passes and how did you handle seki situations?
> 

Passes and Seki's are allowed, it's real Go :-) Apparently white can't
even make a seki (in contrast to 4x4). 

In the ruleset I use, Moonshine-live is death. However I don't think
this matters on 5x5, since you would need an uncondonditionally alive
block separating the moonshine-live from an infinite source of
ko-treaths. It will be quite hard to fit this on a 5x5 board, and
certainly unreachable under optimal play from the empty board.

Anyway, in the case that Benson's algorithm would not provide the answer
the game just continues untill both sides decide to pass. After 3 (but
this may as well be 2 or 4) consecutive passes Benson is called again.
Stones surrounded by unconditionally alive blocks of the opponent are
death if they cannot make two eyes. Everything that's undecided, such as
seki, is assumed alive.

Erik