[andyfox]

"What hands are you giving the BB that you can't bet that river? And given that range, why are you calling the turn?"

It's a question of what hands BB will call that scary river card with. Many players will check-call with two pair or a set here but fold what had been top pair on the turn.

On the turn, the Dude has as many as 10 outs and there's even a chance he has the best hand unimproved.