[sangaman]

if he has 9TJ in his hand and was drawing to the straight, he got there on the river and is likely to call your value bet. if it wasn't for that, i think it might be safe to throw out a little bet. if you check, you will probably have to call a fairly large bet if he rivered a flush or a straight. by betting out less than that fairly large bet, you save yourself money because he is unlikely to raise with a middlish flush or a straight.

still, in this particular instance i think the best play is to check and then if he bets, rely on how you've seen him play in the past (if he is aggressive and capable of bluffs, you'll probably call, otherwise fold).