Re: [gnugo-devel] endgame tuning

[Gunnar Farnebäck]

Evan wrote:
> > > +
> > > +?OO
> > > +a..
> > > +O*X
> > > +
> > > +;xmoyo(a)
> > 
> > But this constraint can't be right. Should be omoyo(a).
> 
> Oops.  I wonder why it worked, then.

Did it? You didn't report endgame:920 as solved by your patch.

> In general, I think that if all the move does is pull a stone out of
> atari, the shape considerations are relatively irrelevant compared to
> the value of the groups directly involved.  If it is a tactical
> defense and there are other liberties, then shape may well still be
> relevant.  Of course, I could be wrong about all that, but that was
> the logic behind the change.

I would say that giving the shape bonus is questionable in all cases
for this pattern but pulling out a string in atari often deprives the
opponent of easy eye space. Actually a tactically captured string with
remaining liberties might even have a fair bit of aji, so it could be
argued that it's more important to draw out a string in atari than one
with liberties. I guess the bottom line is that I can accept reducing
or removing the shape bonus overall but that I don't see a strong case
for differentiating with respect to liberties.

/Gunnar