Obviously we'll never know for sure and all we can do is speculate, expecially considering the fact that James had better defense and could roll with punches better than Hagler. Both fought incredibly hard punchers in their careers.

But for going the distance TWICE with dynamite fisted HW Sam Peter and surviving some real bombs from him, I gotta give the nod to old hardheaded James. Hearns and Mugabi could punch with the best of em, but you can't compare 160lb punchers with a 240lb puncher like Peters.