Beginner Exercise 107 / Attempts

White first.  

Jasonred Here's my attempt at this... my thought was that it's either 1 or a, because b seems to lead the path of bulky five, and c definitely leads to squared six in the corner... actually, quite a few points here other than 1 and a seem to lead to bulky five type things, but I'm not sure, with that extra liberty?

ChrisSchack As best I can tell, this is a rectangular six in the corner with a single outside liberty - just a bit of a strange one.

unkx80: Yeah, it is slightly strange. Any other takers before I reveal the solution?

Simple Ko  

Confused: The best I came up was this sequence. By playing 3 outside and not at a, White needs to win only one ko to kill the group.

unkx80: This is the solution I am looking for. =)

What about this?  

nicky24?: What about this?. When white plays 1, Black has to Connect at 2. Then White plays in the Vital point?

Or if Black plays at a, White plays at b

Refutation  

symplicity: Black is alive now. This both defends the cut and makes maximum eyeshape.

Dead.  

I'm weak, but: can't white kill unconditionally? a, b, c and d can all be answered at e. e is answered at d. f is answered at b, leaving black with one eye (white can almost fill to a dead shape no matter what black does).

unkx80: If , then Black b, White e, Black d lives with two eyes.