Question about Marciano Vs. Louis

Thanks for the responses.

Joe Louis said in his autobiography that his age caught up with him in the 7th round. He said he was busting up Rocky pretty good with his jab before then. He said he felt great until the 7th.

Maybe Lou Duva meant that Rocky could have finished Louis in the first round if he really wanted to? So conflicting.

Still, if an old Joe Louis did moderately well against Rocky, makes you believe he would kill him during his prime. But like someone here already said, Rocky was not in his prime yet either. So it was a somewhat green, (but powerful) Marciano against an old Brown Bomber.