Pitty pat punches wouldn't be causing damage like this. Just because Calzaghe is too fast to see properly, he is still accumulating and accumulating and damage gets done. You contrast it with someone throwing 50 punches a round. Maybe they cause some damage, maybe not, but the other guy is likely keeping up with you with a workrate like that. With a 80-100 punches, nobody is keeping up with you. That's what lost Cotto the Mayweather fight, not enough work to make it clear. He did do well though in winning some rounds, but he only threw 40 punches a round. That's pretty low.