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KyuExercise1

 

Kyu Exercise 1 Attempts
    Keywords: Problem

[Diagram]
Live?

Looks alive to me... if White has sente, should it go like this? Where B4 fills at BC again?


[Diagram]
Not sure, but I think so...

If it's Black's turn to play, it turns out like this? With White alive once again?


[Diagram]
How about this ?

Dieter


[Diagram]
Ko

SnotNose: Looks like ko.



(Moved from Kyu Exercise 1 Solution).

[Diagram]
Status?

Dead, I think - Floris

Dieter: This doesn't prove it is dead, but that it is killable. Is it dead already or unsettled? If so, White can live in ko or live?

unkx80: To put it more directly, when a problem asks for the status of a group, it is effectively asking two questions. 1) Black first to play, what is the best result? 2) White first to play, what is the best result?



[Diagram]
White First

SnotNose: Alive. Classic [L+1 group] living shape.


[Diagram]
Black First 1

SnotNose: Dead. Classic [L+1 group] kill.


[Diagram]
Black First 2

SnotNose: W2 doesn't work. Here is one way for Black to kill. There are others.



[Diagram]
Black to kill

Rafael: SnotNose says B1 kills. So this is another problem. After the solution to the original problem is settled, this one could be moved to its own page.


[Diagram]
Black to kill

unkx80: I think B3 kills "unconditionally". What I am not too sure is, what if W2 is played at B3. I thought it should be a ko.

SnotNose: a and b are miai for the kill.


[Diagram]
Black to kill

SnotNose: I think unkx80 is right (that perhaps W2 yields a ko). If Black insists on going for a kill, he will have to ignore W4 I think. (The BC stones steal the eye at the edge after a throw-in so Black need not respond to W4 right away). Thus, Black can try for the kill with B5. Continuation in next diagram.


[Diagram]
Black to kill

SnotNose: Unfortuneately, Black cannot chase White all the way to the edge because he is short of liberties. I think the best Black can do is jump out with B9 and fight on the outside. Black is full of cutting points so I think White can break out.

I believe this is the only chance for a kill. Since it fails, White should be at worst alive in ko. Here's one way for ko.


[Diagram]
Black gets ko

SnotNose: W6 is a good move and almost makes a living shape. B7 through B9 are all forced. Any deviation from these lets White live (I think) unconditionally.


[Diagram]
Black gets ko 2

SnotNose: Another ko.


[Diagram]
No ko

SnotNose: Black a, white squeeze at b. No ko this way.



This is a copy of the living page "Kyu Exercise 1 Attempts" at Sensei's Library.
(OC) 2004 the Authors, published under the OpenContent License V1.0.