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Big Question Mark Problem 8
    Keywords: Life & Death

[Diagram]
Diag.: 1) Status ?



[Diagram]
Diag.: 2) The killing sequence?

Looks are very deceiving... It looks as if black is unconditionally alive. But as white 1 hanes and white 3 makes a placement, the aji caused by the marked stone becomes apparent and I believe that black is now unconditionally dead.



[Diagram]
Diag.: 2a) The killing sequence (2)?

BillSpight: Doesn't W 3 kill, too?


[Diagram]
Diag.: 2a) The killing sequence (2) - Continuation 1

unkx80: Agreed.

Notice that black can't play at 5 at 6.


[Diagram]
Diag.: 2a) The killing sequence (2) - Continuation 2

Looks like this page needs WikiMasterEditing soon. :-)




[Diagram]
Diag.: 3) Variation 1

With black 1 white answers at 2. Subsequently, 'a' and 'b' are miai.

TakeNGive (11k): Looks like not quite miai. If Black 'a', White 'b', then Black 'c' seems to give a seki. (On the other hand, if Black 'b', then White 'a' captures all the Black stones.)

Good point ! I give an improved variation below (Maybe the reason why it is better not to number them) --Dieter


[Diagram]
Diag.: 3) Variation 1 improvement

... and Black can't play at A because of damezumari. So if he captures the two stones, White kills him at A.

DieterVerhofstadt (1k)

(Sorry for the mistake, and thank you to Dieter for the correction. However, I never numbered the diagram when I first posted the solution. :-) --unkx80)


[Diagram]
Diag.: 4a) Variation 2

Black 1 tries to expand the eye space, but with the ataris at 2 and 4...


[Diagram]
Diag.: 4b) Variation 2 (continued)

...white continues his atari sequence, and occupies the vital point of 4. Black dies of a bulky five shape.


[Diagram]
Diag.: 5) Variation 3

Connecting at 1, and white responds with 2. Then 3 and 4 are also miai.


[Diagram]
Diag.: 6) Variation 4

Capturing a white stone at 1 is also useless. White can cut at 2, black 3, and white 4, and black is again given the death sentence. If black 3 plays at 4, and white can atari at 3, reverting to Variation 2.


[Diagram]
Diag.: 7) Variation 5

Maybe this variation is not needed? In response to black 1, white cuts at 2 and ataris at 4, capturing the three marked stones.


[Diagram]
Diag.: 8) Variation 6

We shall now consider black's other answers to the hane (the marked stone). Black 1 is a possible move, but white 2 reduces black to a bulky five. If black plays 3, white plays at 4 and 'a' and 'b' are miai. Well, white 4 must never play at 'a', or else black ataris three stones at 'c', white 'd', and black 4 makes two eyes.


[Diagram]
Diag.: 9) Variation 7

If black plays 1, white makes a placement at 2 and black suffers the fate of a bulky five.


[Diagram]
Diag.: Variation 8

This way of resistance is also useless. Perhaps the other variations are unnecessary?

--unkx80



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