Position of the week.

So I've decided to do positions of the week. Should be more manageable than a puzzle everyday. Feel free to post any analysis, or ideas. I would rather this be human generated analysis than computer. As computer will solve it, and humans can discuss the ideas behind moves. Anyways, have at it!

Second Player to move (...18)

My initial take on the position would be (18.h5). The idea is to push the current chain towards the top, joining the regions and preventing second player from achieving a second chain. I figure after that, first player looks to sac the 4 chain in the center and split the board, to which I believe second player would capture all boxes and maybe look to move (...20.f9) forming a loop. which would appear winning for second player from my stand-back analysis, no hard calculating. I would just wait to see what my opponent would do and counter correctively. Though I'm sure there might be a possible win for first player in this position: (18.h5) (19.sac4chain) (20.f9)

Let me know what you guys might have come up with.

Typo above, I meant to say preventing first player from achieving a second chain.