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Referenced by
KanazawaProblem20B

 

KanazawaProblem20bSolution
   

Main line

[Diagram]
Main line

W1 is the only move. The only correct answer for Black is at B2. White's correct answer is at W3, and note that White must capture the black stone at W5, resulting in ten thousand year ko.


Variations

[Diagram]
Variation at 2

This dies easily.


[Diagram]
Variation (ii) at 2

Deathe in bulky five. If Black continues with atari at a, White simply connects at W4.


[Diagram]
Variation (iii) at 2

After W3, a and b are miai.


[Diagram]
variation (iv) at 2

Resistance at B2 is useless here.


[Diagram]
Variation (v) at 2

The black group dies as well: a and b are miai.


Failure

[Diagram]
Mistake at 3

If White plays at 3 here, Black lives in seki: either he makes seki at a, or if White plays there, Black can timely capture her bent four.



[Diagram]
Mistake at 1

With the clamp at B4, Black lives.


[Diagram]
continuation

If White plays at a to prevent a seki, then Black plays at b to form a bent four living group.


[Diagram]

After B8, White is short of liberties and cannot play at the marked stone to form a bulky five, so Black lives.


[Diagram]
Variation after the mistake

White 4 here doesn't work... after B6, White is caught in a connect-and-die.


[Diagram]
Another variation

Same fate here if White chooses to take the ko at 5 instead.



Mistake upon mistake upon mistake

[Diagram]
MMM

In KanazawaProblem20 the marked stone was already a mistake. White's hane - as we now know - is another one and then B4 is yet another one.

White 5 makes miai of a and b: b would enable White to almost fill Black's eyespace with a bulky five and White a would make an eye inside Black's group. If Black rushes to capture White's stones, he's left with a farmer's hat space inside his group.



KarlKnechtel (~14k)

Can't Black also live by escaping with a monkey jump in this case?

[Diagram]
Escape?

[Diagram]
Escape?

No escape. --unkx80



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This is a copy of the living page "KanazawaProblem20bSolution" at Sensei's Library.
(OC) 2003 the Authors, published under the OpenContent License V1.0.