I have been only playing at the table for about 20 minutes and really don't have a read on the villian. It's a 5/5 $300-$1,000 NL game. I have $1,000 and the villian has about $650. Folded to the button who raises to $25, the villian who is in the small blind calls and I make it $100 with KK in the big blind. Button folds and villain calls. Flop is J34 rainbow. Villain checks and I check behind. (I sometime take this line to induce bluffs on future streets and/or pot control when heads up and in position.) Turn is a 7 Villain bets $100 and I just call. The river is a 9 and the villain goes all-in for about $450. The bet seemed to be very quick and without much thought. I try to put the villain on a hand that makes sense and I really can't. Thoughts?