caranthir: Why should we accept, after B19D19B18B17G19F19, anything other than connecting at H19? If A18 or A19 instead, then the opponent should take at H19 and now they either have a ko if we block or can possibly escape to the side if we don't.
shai: The branch with throw in at A17 loses a point so it's inferior. Never the less, if that's acceptable, then continuing with A15 after black captures at At16 is in the solution, but B15 and C15 instead of A15 should also be accepted.
caranthir: S15 was already accepted. I accepted R15 too. You have a point; this branch is suboptimal anyway.
Marked non-H19 moves as wrong.