BQM 400

    Keywords: Question

here is a tsumego that I saw during a 5d (blitz ^^) game on kgs

none of the player added any stones to protect against it: they pretty much ignored the position.

[Diagram]
Keisuke (white) vs vaak  

whole board now ^^

So, the ugly black group on the left seems (to me) killable. What would have happenend had white played the marked stone ? there are lots of differents endings, but I'm not sure of the best line of play (I'll bet seki or Black dead)

What do you think ?

[Diagram]
Keisuke (white) vs vaak  

Herman Hiddema: Here's a line of play. B1 is the key move. If white defends the cut at B5, black can play at B9 and live. If white does not defend the cut, but plays W2, then after B3 and W4, black can cut in sente. After the throw in of B7 and W8, black plays B9 and white is unable to connect due to damezumari. Thus black captures three and makes an eye, with another eye at a.

atulab: cant w play 10 at b ? thus destroying black's second eye. I think this leads to a double ko but I think white can actually win it.

[Diagram]
Keisuke (white) vs vaak  

fractic: If white plays W1,W3 to destroy the eye (black can't play a), then black plays B4 white at the circled stone. Black now exchanges B6 for W7.

[Diagram]
W8 above W6.  

fractic: If black now plays at B1 then W2 can try and kill. It looks like double ko but it isn't. The best I can find for black is the sequence up to B9. White then takes the ko and black needs a huge ko-threat.

[Diagram]
seki  

fractic: But black has a better play at B1 getting a seki.

[Diagram]
Keisuke (white) vs vaak  

Jeff: Black's dead, imho. If black doesn't take B2, white does, again resulting in only one eye for black. To live, black would need to skip B2 and instead kill the marked white stones. But I can't read a way for black to stand a chance -- white escapes to the center in every variation I tried.

Herman Hiddema: black should play first, the marked stone was the intended killing move.


BQM 400 last edited by Dieter on July 5, 2008 - 12:49
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