If Floyd Mayweather...

Floyd has beaten far superior opposition to Zab. If Floyd lost like that I reckon the opinion would be that he'd stepped up too far in weight Good point.

Well, its one thing to get rocked and then run and grab if you're trying to weather the storm, nothing wrong with that. But it took Judah two and a half rounds to get any sort of legs under him (round 10 is when he finally looked like he somewhat had his wits about him). Say what you will about Cotto, but he did recover both times relatively quick (I know it took about 2 minutes to recover vs Corley, but he did it inside the same round). As for your initial question, I think Tyrant answered it perfectly.

Floyd has beaten far superior opposition to Zab. If Floyd lost like that I reckon the opinion would be that he'd stepped up too far in weight

Yes that is true. It isn't like basketball where they play 2-5 times a week... with fighters having 2, 5, sometimes 10 months to a year between fights...you can't be anything BUT as good as your last fight... Mayweather got rocked vs Corley, but regrouped himself...got serious...and won the round even scoring what SHOULD have been a knockdown vs Corley...then he went on to dominate and take Corley down a few times... Judah on the other hand, got rocked, RAN, grabbed, then just basically gave up the titles by doing nothing for 6 rounds probably hoping to just walk away with a close Pineda like decision... Mayweather dominated his last fight vs a name and former world champ...Sharmba was no Hatton or Cotto...but he wasn't Balthazar (as Joel Judah calls him..lol) either...