Four stones on the third line in the corner

   
[Diagram]
Four stones on the third line in the corner  

This is the Four stones on the Third line in the Corner and we're looking to explore whether this is unconditionally alive if white plays first.

Clearly, black can play first to kill. But the value of this move will vary based on whether white first kills or only makes ko/seki.


Everything here is therefore to be taken as research in progress not as final conclusions.


[Diagram]
White first  

This seems to be the best path if white plays first, making A and B miai for life.

[Diagram]
Life  

This W1 is simple and less dependent on the outside.

[Diagram]
Double-Descent  

Playing at (3) seems to be a mistake - b can make ko:

[Diagram]
Double-Descent - Ko  

White starts the ko by taking (1).

[Diagram]
Double-Descent - Also Ko  

This latter path looks like seki, but since 6 in the corner is a dead shape, it's not.


Four stones on the third line in the corner last edited by Slarty on February 13, 2012 - 21:31
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