Mel was always going to have a short career due to his style and his mentality. For all his speed he had a bad habit of always wanting to exchange when he necessarily did not have to. Not to mention he ran into Chavez in a fight he absorbed tremendous punishment in. Marvin for sure was past his best and Leonard saw that but to perform like that in a completely different weight class after not being in the ring for years was amazing to see and Marvin could still have beaten 90% of the middleweights on that night he was still that good. Shane had 8 fights after Mayweather and he won a total of THREE that is not a sign of a boxer at the top of his game or someone that is one of the best boxers in the entire world. Duran AFTER the Leonard loss went on to win multiple titles at different weight classes.