It's no secret. If you are any kind of boxing observer and know of great boxers/fights, it was a easy call. Mayweather would definitely win 9 or 10 rounds against Manny every single time. He's not gonna get hit clean in a fight like that if he's 100% and KNOWING Mayweather
If many could win 2-3 rounds as you state in your fantasy scenario.. what makes you think it would just stop there at 2-3 rds?? especially since we know Pac not gassing..
Now as good as Mayweathers defense is.. Lets be honest, we've seen that shyt penetrated and we've seen that nikka get touched..
Old Oscar did it.. Wasn't supposed to happen either
Shane did it too... before he gassed out
And I guess Floyd "LET" Cotto touch him as well...
EDIT Oh I forgot about Zab
Now imagine a prime 145lb Pac in the ring with Floyd.. Pac was and still can be an offensive machine.. and Floyd still hasn't dealt with anyone on prime Pacs level offense yet...
so what exactly are you basing Floyds victorious 9-10 rounds on??