There can be more than 3 kos in a cycle.  There are some pathological cases
of loops involving captures of two-stone groups, but I've never seen this in
a real game.

Here are some example odd positions:
http://www.cs.cmu.edu/~wjh/go/rules/bestiary.html
http://www.goban.demon.co.uk/go/bestiary/molasses_ko.html

David

> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:computer-go-
> [EMAIL PROTECTED] On Behalf Of Jason House
> Sent: Tuesday, July 22, 2008 8:19 PM
> To: [email protected]
> Subject: [computer-go] Super ko in random playouts
> 
> I now tracked down another super ko bug.  I'm curious if anyone has
> worked out which infinite cyles can occur in random playouts that avoid
> eye-fills and suicides.  Additionally, how do people handle this type
> of situation in playouts?  I believe libego checks game length and
> assigns "no result" if the game is too long.  This certainly seems
> simple enough to do...
> 
> A single ko will either be a capture when one side takes it or else
> it'll be legal to fill the ko when the other side passes from no legal
> moves left.
> 
> A double ko can end up with one side owning both ko's, so either the ko
> will naturally do a capture, or filling a ko will be legal.
> 
> A triple ko occurred in the attached game.  It's 3 ko's between two
> eyeless groups.  Each time a color can move, it owns 1 out of 3 ko's,
> and has only one legal move option, take the only legal ko (according
> to simple ko rules)
> 
> Can any other triple ko situations occur?  What about more complex ko
> situations?  I think the triple ko is the only case, but I have not
> rigorously proven it.

_______________________________________________
computer-go mailing list
[email protected]
http://www.computer-go.org/mailman/listinfo/computer-go/

Reply via email to