Broner waits for people to make mistakes, which doesn't work at the top level. Floyd coaxs people into making mistakes. Also Floyd is faster, better defensively, hits harder, more active, and can fight on the front foot or the backfoot depending on the needs rather than acting like every fight needs to be a defensive masterpiece.
Floyd is more gifted as well as a fighter who worked much harder. Floyd lived the life, didn't balloon in weight in between fights like Broner. It's an insult to Floyd that Broner gets mentioned in the same sentence.
Ring IQ, Mayweather has it in abundance, Broner can't even spell IQ. I for one never believed the hype in Broner, I could see the differences. Footwork - Mayweather is agile, fluid, great lateral movement, perfectly balanced. Broner is flat footed in comparison. Defence - Broner's defence involves a bad impression of a shoulder roll and his head movement is basically him leaning back. Mayweather's head movement in comparison is more than just a lean, he slips to either side, ducks, rolls, etc. His guard shifts from the shoulder roll to a high guard, to a slip and slide guard, he also parries shots. Discipline - Mayweather is a gym rat, makes weight comfortably and we've never seen him gas or even look tired in the ring. Broner has failed to make weight before due to him draining himself to pick on smaller men, he is known to party way too much and not train as hard as he should, he does tire in the ring and he loses much of his speed when he does.
Broner is clearly someone who has forever been surrounded by yes men who refused to tell him what needed to be said. Not everyone is blessed with the gifts of others but you can try and compensate with improvements on other things. Broner however doesn't care about that. He just does what he wants when he wants and I don't even think he cares about wins and losses.
Mentality. That's what Broner lacks. That's what guys like Golota, Judah, Tyson, and Vargas lack. They all tend to mentally break down when they're getting their butts kicked, or when things aren't going their way. That's just a few names. There are many more. That's one thing people don't give Mayweather enough credit for. In the instances where the other guy was roughing him up, he never lost focus. When Corely hurt him, he shook it off and was backing Corely up by the end of the round. Same with Mosely. Against Castillo, he never lost focus, he was just in with someone that wasn't easy to figure out, coupled with an injury. Now there are two times I recall seeing Mayweather with a genuine "oh s*ht" look on his face. Times when he looked a bit shook - against De La Hoya, and against Maidana. Still, he figured them out. So what's all this got to do with Broner? When the going gets tough, Broner is about as useful as a used condom. I would not take Adrian Broner to war with me, nor will I stand beside him in any of his future endeavors. I mean for crissakes, this guy is 29, makes a decent living, has raw talent and athleticism to die for, has had some success, has every Fing reason in the world to stand out this time, and he blows it. He was scared of a 40-year-old part-time boxer who has been to hell and back. This fight tonight proved everything you need to know about Broner as a human being. This is the nail in the coffin for him. No more for him. He's done. Best he can do is to be a gatekeeper somewhere. I mean, when they showed him in the locker room, my eight-year-old nephew said "he looks scared". Everyone else was like "yeah, he does look scared." I kissed my $100 goodbye right then and there. At no point during the fight was I thinking there was any possibility Pac would run into something. Broner's counters were for show. He was Charlie Zelenoff throwing punches from behind the counter, pretty much. But to end on a positive note - I give Pacquiao credit for being a 40 year old part time boxer who can still look good in there. Say what you will about Broner, but he is a step above a few guys who were slapping Roy Jones around when he was Pac's age. Pac looked better than Mayweather did against Berto and Mcgregor. Pac does not look like complete s*ht by any means, or at least, he didn't last night. I think Pac can still be fairly competitive with some of the more elite fighters within his weight range.
Broner is a one pace counter boxer who's timing isn't fantastic (timing is the most essential skill for a counter fighter) Struggles to adapt during a fight. Has a low punch output. Floyd mayweather has incredible timing, the ability to adapt his pace and style during a fight, great jab, fast hands, a repertoire of tactics and traps at his disposal. Doesn't have a particularly high punch output, but that's by design so he doesn't waste energy punching air and gloves.
When Mayweather enters training camp he works primarily on technique ,strategy and improving his skills. Broner on the other hand will spend the majority of his time in camp focusing on trying to lose the weight he puts on between fights. At the top level they all have the talent, what separates the elite fighters is they have the mindset of an athlete all year round. As Others have mentioned Broner lacks the Attitude, Discipline and Work Ethic of an elite level athlete. Added to this the people he surrounds himself with outside of the ring are a bad influence, by the time Broner matures and realises his mistakes, it will be too late.