312SS Notcher

    Keywords: Life & Death, Shape
[Diagram]
312SS  

This is quite an interesting notcher. Black can easily live by playing at a, the vital point. That's also where White has to play to kill Black.

[Diagram]
312SS  

When Black expands eyespace with B2, White builds an eye in the stomach with W3 and W5. Now either White will complete this eye, or if Black prevents this, White will almost fill the eye shape with a bulky five.

[Diagram]
312SS  

This time there is only gote seki in the hane. (Reverts to 311SS.)


[Diagram]
312SS with hane  

Things get somewhat different when there is a hane at black+circle.

[Diagram]
312SS with hane  

The killing sequence that worked for the 312SS notcher without hane does not work here. B6 captures the W1 stone to make the second eye.

[Diagram]
312SS with hane  

If W3 here, then B4 makes seki. Subsequently, a and b are miai.

[Diagram]
312SS with hane  

Oshi-tsubushi prevents White from killing with a bulky five dead shape.

[Diagram]
312SS with hane  

But W1 kills. B4 and W5 are miai.

[Diagram]
312SS with hane  

B2 can't save the Black group either.

[Diagram]
312SS with hane  

Neither can this B2.

[Diagram]
312SS with hane  

Black can't make seki either.


312SS Notcher last edited by Unkx80 on October 15, 2008 - 12:24
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