Mosley is fast and he is stronger than Mayweather.
I think Mosley's best chance is to jump on Mayweather early and hope to catch him with something.
If he doesn't take him out early, I feel Mosley will tire as the fight progresses which will give Mayweather the time to pick him apart.
And you just never know, Mosley just might get old tonight the way Dela Hoya did against Pacquiao.