Ezzard Charles at number 5 is well within reason, given that he may well be the best light heavyweight in history and ruled at heavyweight. Spinks is an easy Top 5 at light heavyweight and also ruled at heavyweight. He deserves to be rated highly. Ali has Liston, Frazier and Foreman on his resume. Holmes doesn't. As for Mayweather, this list was created in 2013. At that time, his rating was appropriate.