BQM 257

Black to play and live  

The correct answer according to the site is a. However I fail to see why b isn't also correct. If black b and white a, black can then continue by capturing the stone which is in atari. Why is it not a solution?

Couldn't this work?  

agro1986 (19k KGS)

zinger: The short answer is yes. This way also lives. For a somewhat long-winded discussion of which move is actually better, see /discussion.

Bill: The somewhat longer answer is yes, but.

Black lives, but...  

lives, but it is a bad play.

Huge ko threat  

Thanks to White gets a huge ko threat to kill Black's group.

ilan: You are all wrong! The right move is c.

Black to play and live  

Xanthus: Why would this be better than a? W still has the ko-threat (or even 2 threats if B responds to taking of c with b). I'm not even sure if it is better than b, because it is a point worse if white defends, even though it might generate a (small) ko-threat for B.