JCC was undefeated for something like 15 years and was 89-0 when he lost to Frankie Randall. That's a little more impressive, being twice as many fights that one could possibly lose. There were a lot of Tijuana taxi drivers in that bunch, but anything can happen in boxing and to go 89-0 is pretty good.
Robinson has questionable and highly booed decisions in that streak too, including Marty Servo and Basora. Still, that 132 mark is incredible, but he wasn't without his question marks.
Because the best guy Floyd faced was an faded Oscar Delahoya who gave Floyd fits ,I think its safe to say that Leornard would have been too much for Jr .
Well Floyd made a nice statement before "You have been looking for the gameplan to beat me for almost 20 years, obviously there isn't one" Well I do think it's possible for Mayweather to get beat but then again I doubt we will see it.
SR. was the first top 10 contender SRL ever faced. Leonard was not yet the fighter he would eventually become. Benitez, Duran, and Hearns were levels above Sr.