Re: [gnugo-devel] evan_5_1.2

[Arend Bayer]

On Sat, 6 Sep 2003, Evan Berggren Daniel wrote:

> On Sat, 6 Sep 2003, Arend Bayer wrote:
>
> > I have two remarks about this:
> >
> > 1.) The move at * wouldn't have occurred to me. Then I checked with
> > kombilo (I really recommend installing kombilo to everyone interested
> > in joseki study -- whether for gnugo or for your own games), and I indeed
> > did find it in a lot of pro games. But they were all in the following
> > situation (or similar):
> >
> > -------------+
> > .............|
> > .............|
> > ..aX......*..|
> > ...,.....X...|
> > .............|
> > ..........O..|
> > .............|
> > .............|
> >
> > In all the games, X had a stone at the hoshi on the left side, or as
> > in  the diagram, or at "a". What is the reason behind this?
> > Usually, the variation in the diagram above (without a pincer) is bad for
> > white. But when it's played in the situation as in the last diagram,
> > the black stone on the top ends up badly placed, thus leading to
> > a fair result overall.
>
> I think there is more to it than that.  The patch was in response to the
> testcase nando:210, etc, which was taken from a pro game.  In the
> testcase, there is no extension.  I confess I do not know why the invasion
> was chosen; presumably there is some other reason that the sequence played
> was reasonable.

In that case, if White had followed the joseki as you (correctly) added
it, Black would have had a wonderful followup move around M3
devalueing White's thickness.

> > So I think the joseki needs a little more context. Maybe we should merge
> > the patch as it is, however, without marking W1 above as joseki.
>
> I like that approach; expecting gnugo to decide when an invasion is better
> than something else like a double kakari seems unreasonable to me.

Done.

Arend