Who would beat mayweather at...

sure

 

After castillo 2 he became more defensive and stopped being the toe-to-toe fighter he once was.

 

Wright

 

Nelson would be the fun wildcard at 130, that would be an awesome matchup.

Above 140 there would be plenty. At 140 there would probably be a few, any guys who can put a lot of pressure on and work at a very high rate yet are highly skilled would give him big problems. Guys like Chavez and Pryor, also a speedster like Meldrick Taylor could probably win on volume. Surprised people are mentioning someone like Tszyu and no Meldrick Taylor, i can't see Kostya beating Floyd to be honest.

The only person below 147 who actually beats Floyd's ass is Duran.

 

147-154 there'd be a whole heap who were at least 50-50 or favoured.

130-140 would be a small list. Extremely small to nil at 130, countable on 1 hand at 135, and a handful at 140.

I'm sure they've already been listed in this thread though...

 

No one is going to have an easy time with Floyd Mayweather Jr.
Not even those who would beat him. Mayweather can be a slow starter as he adjusts to his opoents style. In the early rounds there is the opertounity to jump on him and get an early lead. Zab Judah, Oscar De La Hoya and Ricky Hatton had early secuess against him. In the end Mayweather took over and was clearly the better boxer. The key to beating Mayweather is get him to come to you. When Mayweather goes backwards and to the ropes it is a trap. The thing about getting him to come to you is that he is also a very effictive boxer coming forwards as well a backwords. You have to have to have the speed and skills to counter and get out.
this being said.
130: No one
135: Benny Leonard, and Prenell Whitaker. I need to see more of Ike Williams to make a decison about him.
140: Wilford Benetiz, Aaron Prayor, Whitaker
147: Ray Leonard, Whatiker. Tommy Hearns, Benetiz.
154: He has only one fight at this weight beating De La Hoya who was still very good at that weight, but It is hard to tell

 

The Duran of the first Leonard fight would have given him a thorough beating.

I would take Whitaker and Duran to have the best chance at Lightweight. And would probably get the better of him all the way up to 154 lbs.

At Light welterweight I think Pryor would over power him. To much pressure for Floyd to handle. Chavez has a decent chance as well although I wouldn't be confident on that one.

Welterweight it is not really known as we don't really know how good he is at the weight. The opposistion has not been the best.

Hearns at 147 and 154 would be a nightmare for him because of the reach and the way Tommy can use that to his full advantage. He is one fighter Floyd would struggle to fight on the outside and pot shot.

Again at 154 he is pretty unproven
People like Julian Jackson may just be to strong. Norris would be a good fight but again the size difference may be to much.

Other than that there are not to many