No way Mayweather loses. If Conor -who has never fought as a professional boxer - comes in and beats one of the greatest boxers ever, then boxing would be completely DEAD! No way Conor stands a chance in this fight. On the other hand, if Mayweather knocks Conor out in less than 3 rounds, then MMA would look really bad. The entire Boxing world and community - along with the casual MMA/Boxing viewers - would then view Boxers as the superior athlete/fighter. I think this thing goes past 3 rounds and I'm hoping that's where the over/under is....that would be my bet.