Roy Jones is a guy with great athleticism. He is a man with great speed and in many sports; you can get away with murder when you are as fast as Roy Jones is.
However, Roy Jones is not young man anymore. He has slowed down somewhat. Sugar Ray Robinson was a technical boxer and so was Ezzard Charles. And even today Bernard Hopkins has great technique when it comes to Sport of boxing therefore these guys were able to last a little longer in a young mans sport. Calzaghe is a Blue-collar boxer, his technical skill are good but not great. If Calzaghe does not fall for any of Roy Jones tricks antics, I see him stopping Roy Jones out early but he has to keep a lot of pressure on Roy Jones.