How well do you think Rocky would do in todays CW? Personally I think he'd do well but I don't think he'd be undefeated.
I really can't see anyone in the current cruiser division or any time recently for that matter whom I'd favor to beat Rocky Marciano. There may be a few who could have hung with him for a while, but that's about it.
In the history of the cruiserweight division there are only a few guys I could see possibly beating Marciano. Holyfield at cruiserweight is one of them and I'd give a small chance to James Toney or Qawi but I'd favor Marciano against all of them.
I have stated this same thing for years. Talk about his sad measurables till your jaw drops, Rocky was a full blown motherfukker in the ring. Watch the tape. He was next level.
He would be great. The thing is, if he fought post 1980, he'd come in heavier. Almost everyone does some bodybuilding, and even without weights, consider that in his era they bought fighters in as low in weight as possible.