Xuanxuan Qijing Problem 13 / Attempts

[Diagram]
(1) Moves 1 to 5  

W3 is the key move. Ko.

[Diagram]
(2) Moves 1 to 7  

again Ko.


[Diagram]
(3) continuation 1  

tderz: where is the ko here ?

[Diagram]
(4) continuation 2  

tderz: this is ko about W8 as Black cannot simply connect at B6 as there there is the cutting point a.

[Diagram]
(5) continuation 3  

tderz: Hence, as diagram (2) does not necessarily seem to end in ko (cf. proof diag. (3)),
and white+circle here is not necessary to create the eye e,
white+circle is not efficiently placed.

[Diagram]
(6) continuation 4  

tderz: Only when changing the order like this,
Black seems to be forced to follow diagram (4).

[Diagram]
(7) continuation 5  

Dave: It looks like White has to make Black decide how to reply before determining how to continue in the corner...

[Diagram]
(8) continuation 5a  

Dave: If Black captures at B1, White can now play W2. If Black tries a hane (B3 or B5 first), White throws in on the opposite side (W4 or White a) and gets a ko on one side or the other after W6...

[Diagram]
(8) continuation 5b  

Dave: If Black descends at B1, White forces with W2 and then lives with W4 since Black can not play at a due to shortage of liberties.

[Diagram]
(8) continuation 5c (B7 connects)  

Dave: If Black continues on the right, then White is able to force Black on the left before living with W8.


Xuanxuan Qijing Problem 13 / Attempts last edited by tapir on December 27, 2009 - 15:03
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