--Boardwalk
I'm only a beginner but this is my attempt at a solution.
I think the only place that will allow blacks group to grasp for life is at .
If is followed by
and
, in order to protect whites investment in the corner, then
extends down the right side and can either be sealed by
and
but will allow black's group to live.
While this contains black from spreading down the side but black can now attack the corner preventing white from gaining enough eyespace to live.
Either way black isn't in as strong a position as he could've been without the hane. He has the chance to recover the corner but would lose influence towards the right side and center.