Beginner Exercise 300 / Attempts

ko  

I think B can force a ko

unkx80: Wrong sequence - at a lives.

ko continued  

Ko to kill.

Slightly different ko  

No. White would get 2 eyes if it responds to 5 with 8. If black move to 6 after that, white's move to 9 will protect 3 stones in upper right.

What about this defense?  

a,b and c,d are miai pairs for W to live.

Black should start this way to kill.  

is needed to avoid falsification on top. If at then at a.

Reuven: Sorry, can still be played above and keep the second eye here.