Kyu Exercise 1 / Attempts

Sub-page of KyuExercise1
[Diagram]

Live?

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

[Diagram]

Live?

ChaoSpectre: Fills at BC? Do you mean fills the ko? What about 9 here? Also, is it possible to extend from W1 while retaining the corner (S)? I realize that it is not important to the status of the group at this point but...

[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 /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) 2005 the Authors, published under the OpenContent License V1.0.
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