Sub-page of KyuExercise45

Problem I


LukeNine45: I believe White can live at a and black can kill at b, but I could be wrong because I didn't spend much time looking at it...

Hans: If black 1 white 2 is interesting (even if it does not bring life for white).


zinger: carrying on from Hans' W2, W6 seems to give a ko for life. But -

White dies  

zinger: This B1 kills white - there are no eyes at the top now, and only one in the middle.


I saw this for white playing first

zinger: White can live this way, but there is no need to give away a stone at W1. W1 at W3 threatens W1; this is better. See One-Two-Three for more explanation.

Problem II

Ko for Life  

P7A77: I had read the ko response to Problem I before looking at this, but it seems here is the only way for White to live, with Black taking first?

zinger: I think this is right. After a white threat and a black answer, black can conenct at a as a local threat - white must answer at b.

Anon: Black 2 at 3 kills - if white prevents the connection black then plays at 2.

zinger: Aha. Silly me :)


tderz: Anon, you mean like this?


tderz: B4 at W5 is safer. Sometimes the sagari W5 is tesuji for W7+W9=eye, but White is still dead here after B10=a.


[1] If there is a white+circle=circle, white sometimes might want now to try W5 here. (White would start with W1=W5)


But nothing happened after B8.


Anon: Like this

Also Dead  
No good for white  
White still in trouble  

As with tderz's variation above playing hane at W1 first doesn't help with black a, white b, black c to follow

tderz: True, and in dia [1] is B2 a white stone ..


White a and b are mia now. (that's what I meant)
Perhaps it did not make so much sense that I altered a problem and discuss something completely different. I am sorry for the confusion caused ...


Anon: Here black can still play B6 at W7 to kill. White should play W1 and W3 as below for a ko (or directly at W3 below).

black can't avoid ko  

If B4 tries to avoid ko white is alive since a and b are miai. If B6 at b then white descends to a with W7. Black has a lot of moves for B4 which lead to ko - taking the ko immediately is best.

KyuExercise45/Attempts last edited by on April 4, 2005 - 13:14
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