Kyu Exercise 93 / Solution

Sub-page of KyuExercise93

Reference

[Diagram]
Reference  

It seems easier to motivate the solution by first showing this reference diagram, which is actually a failure for White.

White would like to pull out the White stone with W1. But B2 and B4 can capture the three White stones in a connect-and-die, creating two eyes in the process. The question is then, how can White prevent this connect-and-die? The trick here is to reduce Black's liberties.

[Diagram]
Reference  

More elaboration on the reference diagram. It should be noted that after W5, although Black cannot block at B8 directly, Black can first capture the three stones at B6 in sente, before return to block at B8. If W5 is played at B8, the same comment applies.



Solution

[Diagram]
Solution  

The key move is to first make the exchange of W1 and W2 before pulling out with W3.

[Diagram]
Solution  

Due to shortage of liberties, Black cannot connect and atari at a after W5, so the Black corner dies.



Failure

[Diagram]
Failure  

A main difficulty of this problem is to spot the first move in the solution. Playing B1 here instead would be a mistake. Now B4 can capture and threaten to make the second eye.

[Diagram]
Failure  

If B5 throws-in, then with the extra liberty at a, Black can now proceed to capture the White stones in a connect-and-die as originally planned.


Kyu Exercise 93 / Solution last edited by Unkx80 on October 12, 2008 - 20:44
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