Opponent seems to play tight, no specific read though, he is not one of the better regulars, though.

Full stacks. 600NL, 5handed

Preflop: I raise to 16 on MP with , BB calls, Button calls.

Flop (51):
BB checks, I bet 44, Button folds, BB calls.
Turn (139):
BB checks, I check.
River (139):
BB bets 116, I call.

I think river call is quite standard given the way I played this hand.
What do you think about turn check?
If someone folds river, why?

Absolutely no way are you gonna fold that river. I would bet turn because I'd hate for a spade (except or ) or 6 to roll off, hell if he made a loose preflop call with or he just picked up another 3 outs.

Are you checking behind on the turn because you think 66, 55 and 88 is his HD and you're behind that range, wanting to increase bluff equity and get a free card to beat the straight? And that hands that you crush (like 99-AA) will fold to a bet on this scary board?

Once again, no way you can fold the river after checking the turn since he could either be bluffing a busted flush draw or valuebetting a hand you beat, like 55, 78s, an overpair or whatnot.

River call is automatic. You have massively under-represented your hand here, hell you could be on AK/AQ maybe even KQ.

I think I prefer the turn check over a bet. I think a check will induce a lot of river bluffs, and apart from spade draws there's not much to protect our hand from that hasn't already hit. There are only 7 spades to worry about, so it's not quite WA/WB but it's pretty close.