I think Kessler. Because while I believe Calzaghe to be the better fighter, it's obvious that he's scared to death of Kessler.

Much the same reason I think Margarito would beat PBF. I don't think he's near the fighter PBF is, but there's something about that big, ugly, hard-hitting Mexican that puts the fear of death in Mayweather. You can see the bitch in his eye. Once you fear an opponent. You might as well pack it up.