GokyoShumyoSection5Problem9/Attempts

White to play and live by oiotoshi  

After this sequence, Black has to cover c, d, and while White can atariwith a and b. The timing of is important I believe. Dieter

In the first diagram, 9 at b, to avoid the ko below?

black to force ko ?  

atulab: black will most likely lose this ko. However the sequence exists. Is there a problem in the setting of the problem ? in Dieter's sequence ? I don't know (it's 2 am will I'm writing this) ...

good luck ^^

Possible continuation?  

So, with the variation given above, Black can win the ko if he has four more big-enough threats than White does, at the cost of White playing elsewhere twice. And White has two good threat later (taking the ko and putting many Black stones in atari PLUS threatening to save the 8 White stones).

• Note: I took the liberty to change one of the two markings in atulab's diagram to (the other possibility, first and next, doesn't make sense), and based the interpretation off the "corrected" variation. Part of me wonders, though, if in that diagram should be played at in my second diagram, so that Black has less to lose.