I have a bit of a history with this villain. He's pretty crazy, his stats are 50/12/1. He was aggressive preflop but didn't seem like the type to make a river raise with nothing. At the beginning of the session he floated on me a couple of times, so in the past 20 hands or so I've check-raised the turn twice against him after he called my flop bet. Once he folded, the other time he stacked me when my flopped set ran into his flopped straight. I thought that because of my previous check-raises, he'd be scared to bet the turn unless he had something really strong, so I was likely to get a free card from him.

On the river I didn't know what he could possibly have that had an eight in it, but like I said he didn't seem like the type of guy to bluff-raise the river.

PokerStars No-Limit Hold'em, $1.00 BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Button ($98.90)
SB ($97.50)
BB ($100)
Hero ($101.50)
MP ($230.75)

Preflop: Hero is UTG with 3, 3.
Hero raises to $3.5, MP calls $3.50, Button calls $3.50, 2 folds.

Flop: ($12) 4, 5, A (3 players)
Hero bets $8, MP calls $8, Button folds.

Turn: ($28) 7 (2 players)
Hero checks, MP checks.

River: ($28) 6 (2 players)
Hero bets $20, MP raises to $50, Hero??????

Final Pot: $128