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Shape Problem 4 discussion
  Difficulty: Advanced   Keywords: Shape, Problem

[Diagram]
Black needs to correct this shape

Charles Matthews My first comment here is that the shape relationship between BC and BS is never really good.

DaveSigaty: I think that we have to add WC into the mix before we can try to claim that the BC - BS relationship is not really good. When the White stone is missing, it is the standard (5-6 times more frequently played than any alternative) choice for closing the corner.

[Diagram]
Abstract pattern (1)

In this case BC and BS have a good relationship.

DaveSigaty: With both WC and WS on the board the play at BC does not have a very successful record. While the theoretical relationship may be nice, it is too passive. When jumps to W1, the corner is still vulnerable. Black will likely want to add B2 anyway. At this point is he better off with the stone on BC?

[Diagram]
Abstract pattern (2)

And also in this case BC and BS have a good relationship.



So you could say that Black has created himself a shape problem, by taking 50% from each pattern.

In this case:

[Diagram]
The 'big bulge'

I recommend on general grounds this 'big bulge' shape made of two keima.



HolIgor: We have a winner. This is what I meant.

[Diagram]
White cannot lean

A play at a becomes impossible.


[Diagram]
Corner aji

Maybe there are still 3-3 invasion problems at a after BC. Black could try a play like b to keep the corner.



Playing BC, however, seems to get Black out into the centre in good shape. So it looks like good style to me.


Jan: This was my first idea too, but Charles was quicker[1] (but then, I haven't written a book on shape :-). One thing I wasn't sure about was whether the correct solution really keeps white separated. What happens after the following moves? W3 seems to be able to reach the upper-side group.

[Diagram]
White trying to connect


[Diagram]
White trying to connect

Karl Knechtel: I'm not convinced of that. (5-8 are shown to indicate that a counterattack is futile.)


[1]

Charles Not in the book, and of course I cheated with a database (I wouldn't enjoy posting comments without some sort of verification). But 'big bulge' is a term from Shape Up!



This is a copy of the living page "Shape Problem 4 discussion" at Sensei's Library.
(OC) 2004 the Authors, published under the OpenContent License V1.0.