on the river, I change my plan

why wouldn't you c/r the flop or something? Did you really expect him to bet the entire way with something worse than a pair of 8s? Since he's tight passive I'd c/r the flop, bet the turn and see what happens.

[jt1]

CR'ing the flop may be good advice. But I decided to try and see a SD on the cheap. The way I see it is if I was dominated but my kicker paired then by check/calling the flop, letting the turn get checked through, and betting the river, I'm pretty much certain to get a river call. To me, this is better than check/raising the flop and risk getting 3-bet by an overpair.

This was a game time decision but I'm sure I was considering bet/folding the river, until that King spiked.