If PBF took a decent hard shot I think he would go down. Why do you think he works so hard on defence both at range and on the inside? As soon as someone gets on the inside he ties one glove down by his waist and shoves his glove in their face and holds them there till the ref splits them. A decent strong fighter will just smash away at him in that situation. Hatton or Cotto have a great chance.....but thats only if they can catch him.