Kyu Exercise 7 / Solution

Time is of the essence  

The marked black stones have only two turns of aji left in them - the first move is nearly certain to be ate.

Solution  

Now Black better has enough ko threats, or White will finish off on a - this is a two stage ko. b is a ko threat, but obviously smaller than the ko (deiri counting). If Black uses b, White may choose to let Black escape his group, roughly half of the total value.

White fails  

White answers wrong after . Now catches the white group in a snapback.

Variation A fails  

White can also answer with at a.

Variation C fails  

Same result as variation A.