The difference between the first and second fight between Edgar and Penn wasn't BJ, it was Frankie. Where Frankie fought a conservative fight the first time around and didn't get comfortable until later in the fight, in the rematch he came out far more aggressive and clearly had Penn figured out by the get go. I think a third fight between them would look very much like their second, even if Penn decided to use his grappling and go for takedowns more. Remember BJ already tried using his top game BJJ against Edgar and got either completely shut down or reversed. I think Edgar proved he had Penn's number by taking every round in the rematch, regardless how you scored their first fight where I believe Frankie gave BJ too much respect.