Hmm. Raising the turn just might make MP fold the best hand, but I don't see any other advantages to it. It makes 5x fold when I could get another bet out of them on the river, and it certainly wouldn't have gotten me to showdown any cheaper than I got there, especially because in this game a straight draw is calling that raise anyway. Whether a turn raise is good or not, depends on how likely MP is to fold the winner, and I don't make a habit of bluffing, when I don't have a read other than that someone probably likes to call a lot. How likely to succeed do you think your bluff would be here, against an unknown?