[bluffbetter]

On the turn I think he either has a straight draw or nothing, unless you have a read that he bets big when he bluffs but bets very small when he has something good, but I would be surprised if he has a good hand here. So on the river I think you can't bet more than 1/2 pot, beacuse even most loose players will probably not call 3/4 pot or pot with 4th or 5th pair. I don't think the check raise is bad, however. And if you check-raise, I think to bad players it looks like you don't have anything, so checked, and then after seeing their possibly weak smallish bet, you've changed your mind and decided to bluff them, so it's a good play and if they're very loose and aggressive postflop it's the best play.