Re: [gnugo-devel] Half and false eye with ko.

[Daniel Bump]

> > The following table converts diagonal sums to
> > 1/4-fractional eyes. The total number of eyes to live would be
> > 2. For example, a group with 8 quarter eyes should be alive, the
> > example at the end shows. If at any point B takes a ko, W just takes
> > some other one.
> 
> Your example is faulty. 8 "quarter eyes" do indeed live
> unconditionally, but so do 6.

You're right. This is the situation I called a 1/4 eye:

      .X..      better than false eye, worse than half eye
(b')  .XOO      3 < e < 4
      OO.O
      OXOO      e = 2 + b
      X.X.
      .X..

It takes 2 moves for W to turn this into an eye and only
1 for B to deprive W of the eye. So if there are several
of these on the board and both players start taking them
W will get about 1/3 of them. So maybe this should be
considered 1/3 eye, not 1/4.

Dan