Quote Originally Posted by Galapogos
He doesn't always have to have air here. It could just be a hand that would be scared off by a shove on the turn. Sometime he could have a draw here but this board isn't that dangerous, there's better boards for shoving the turn I think.
After his turn bet, he's put $90ish into the pot with $150ish behind. Very few hands are drawing dead to Aces and we're probably paying off the river too, so there is considerable value in forcing him off a live hand. Certainly more value in getting him to shove worse hands on the river, but how often is he going to do that?