Beginner Exercise 42 / Solution

Sub-page of BeginnerExercise42
[Diagram]

White kills

splice: Black has one eye in the corner. W1 threatens to capture BC and kill the eye there. B2 captures the white stone but White extends to W3 and Black has one false eye and one real one. Dead.

[Diagram]

Black lives (6 at 1)

Playing W3 is wrong. It leaves W1 in atari, which is promptly captured by Black. Black makes a second eye and lives.


[Diagram]

What about this...?

Would this work? You take away one of Black's eyes, and also have a net to run him into?

unkx80: This will work too.

victim: But it will give B an extra ko threat. The first solution is better.


Ko threats?

SGBailey:

[Diagram]

From the 'White kills' diagram

There is a ko threat for Black at 'a', with 'b' being the best reply (capturing the two black stones might permit the cycle to start again.)

[Diagram]

From the 'What about this... ?' diagram

Again there is a ko threat at 'a' getting the reply at 'b'. Actually, even if White ignores the ko threat and doesn't play 'b', the best Black can do is capture the two white stones on the edge which, with a throw-in, leads to a false eye.

So the latter diagram isn't even one threat for Black. Thus surely White should prefer this one.

[Diagram]

Extra ko threat

Shaydwyrm: Black can get extra ko threats by playing this way instead of as in the "What About This?" diagram. Now a is a threat (b is the response), and cutting also becomes a threat, maybe a real one rather than just a ko threat depending on the outside situation.



This is a copy of the living page "Beginner Exercise 42 / Solution" at Sensei's Library.
(OC) 2005 the Authors, published under the OpenContent License V1.0.
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