Re: [John.Tromp@xxxxxxxxxxxxxxxxx: Re: computer-go: How many bits are neededto encode an N x N Go position?]

[Robert de Neufville <rden@xxxxxxxxxxxxxxxxxxxxx>]

> Any legal position can be reached just by playing its stones and passing
> for the side with fewer stones. If you want to do it without passes, then
> even the 2x2 position
>  . .
>  X X
> is impossible to reach.
Yes, although I think it is possible for *white* to reach this position...

> For solving arbitrary positions on 5x5, exhaustive search will be required.
> Furthermore, a definite result requires use of some sort of superko rule,
> which means that the whole history leading up to a position becomes
> relevant, and just marking a single ko spot won't suffice. This is already
> apparent in the 5x5 variations I explored at
> http://www.cwi.nl/~tromp/java/go/go.html
> In fact, some variations even depend on whether one uses positional or
> situational superko!
This is very interesting.  But I don't understand. What do you mean 
by a superko rule and why is it necessary?

Best,
--

                                               		Robert de Neufville
                                                
	rden@xxxxxxxxxxxxxxxxx