OK This happened yesterday at a $200 NL cash table. Very deepstacked for me both myself and opponent had $500+ (250bbs).
I know opponent well, we play tgether every day. He is a fairly solid and winning player.
However, he sometimes will call potsized bet on draws. He can also call as a slowplay. He is not the sort of player to call a bet on this flop with a hand like an overpair - he would raise or fold.
If he calls on draw and misses he is capable of bluffing river for sure.
He can be a tricky player, check raise as bluff etc.

I am on BB with 56off
6 way pot

Flop was:

(Pot = $12)

SB checks
I bet pot
button calls

Turn was (Pot = $36)

I bet $30
Opponent calls

River (Pot = $96)

Your play?

Exactly what I did Steve, and exactly for your reasoning. I checked, he bet $40 and I called.

However being totally results oriented he turned over 55 and I know if I reraised to $100ish he would have called so I feel I left money at the table. I also cursed the paired board as if the turn was maybe Q of spades, I probably take all his money!

However busted flush draw obviously folds and full house would reraise me all in, so I guess I made the correct long term play.

check-call river. hope he bluffs at it.
I doubt he has a fullhouse here or quads, if he had either he would have raised flop since there was possible flush and straight draws on the board. If he had a fullhouse hes raising the turn for sure.

His play thus far looks like he's playing a AXs type hand with the FD. With 2 overs. Maybe A6s A7s-A10s. I think A5s would be raising that flop.

I check river, and hope that he hit his ace and fires at the river.