Re: [gnugo-devel] endgame tuning

[Evan Daniel]

On Thu, 09 Sep 2004 03:11:20 +0200, Gunnar Farnebäck
<address@hidden> wrote:
> Evan wrote:
> > Also, it looks to me like something is wrong with kgs:230.  Is it loading
> > the wrong sgf or something?
> 
> Hopefully Arend knows something about it.
> 
> I should take this opportunity to advertize the --check-unoccupied
> option of regress.pike.

Interesting.

> 
> > +Pattern EE806
> > +# evand new (3.7.1)
> > +# see kgs:70
> > +
> > +|.O??
> > +|.OX.
> > +|.*X.
> > +|....
> > ++----
> > +
> > +:8,OXe,terri(3)
> 
> This should be possible to handle with influence tuning but until
> someone does that the pattern looks fine. I'm not sure about 3 points
> of territory, however.

The move is sente and picks up three points of territory -- if instead
the opp is allowed to descend, they get 2 points in the corner, plus
they don't have to connect behind.  This pattern might be too small
for that to universally be true, though.

> 
> > +Pattern CE34
> > +# evand New pattern. (3.7.1)
> > +# see endgame:920
> > +
> > +?OO
> > +...
> > +O*X
> > +
> > +:8,OXe,terri(1)
> 
> Should also eventually be solved by influence tuning.
> 

Makes sense.

> > +
> > +?OO
> > +a..
> > +O*X
> > +
> > +;xmoyo(a)
> 
> But this constraint can't be right. Should be omoyo(a).

Oops.  I wonder why it worked, then.

> 
> > +Pattern CE35a
> > +# evand New pattern. (3.7.1)
> > +# see endgame:850
> > +
> > +?X??
> > +.*.o
> > +O..O
> > +?..?
> > +
> > +:8,OXe
> > +
> > +?X??
> > +.*.o
> > +O..O
> > +?ab?
> > +
> > +;omoyo(a) || omoyo(b)
> > +
> > +
> > +Pattern CE35b
> > +# evand New pattern. (3.7.1)
> > +# see endgame:850
> > +
> > +?X??
> > +*..o
> > +O..O
> > +?..?
> > +
> > +:8,OXe
> > +
> > +?X??
> > +.*.o
> > +O..O
> > +?ab?
> > +
> > +;omoyo(a) || omoyo(b)
> > +
> > +
> > +Pattern CE35c
> > +# evand New pattern. (3.7.1)
> > +# see endgame:850
> > +
> > +?X??
> > +..*o
> > +O..O
> > +?..?
> > +
> > +:8,OXe
> > +
> > +?X??
> > +.*.o
> > +O..O
> > +?ab?
> > +
> > +;omoyo(a) || omoyo(b)
> 
> These all look fine, but I wonder if they shouldn't go into patterns.db.
> 

That makes sense to me.

> > --- patterns/patterns.db      22 Aug 2004 13:07:31 -0000      1.129
> > +++ patterns/patterns.db      7 Sep 2004 02:13:59 -0000
> > @@ -1254,6 +1254,7 @@
> >
> >   Pattern CC81
> >   # db added (3.1.4)
> > +# evand modified (3.7.1) -- see endgame:910
> >
> >   O*X
> >   XO?
> > @@ -1265,7 +1266,7 @@
> >   XO?
> >   ?O?
> >
> > -; does_attack(*,a)
> > +; does_attack(*,a) && lib(a) > 1
> >
> >
> >   Pattern CC82
> 
> This constraint revision doesn't make much sense to me.

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.

Evan Daniel