There is no "greatest boxer", its your opinion on who you think is the greatest boxer, so thats for you to figure out.
Joe lois is a legend.
Floyd Mayweather can't argue with that record there's no way to beat him there was a way to beat Ali and all those guys you named but there is no game plan to fight FMJ
My opinion-
Heavy weight - Muhammad Ali(Bc Tyson had to many problems w/ not training & after he got as good as it gets. This happened twice)
Middle weight - Sugar Ray Robinson
Light weight doesn't count
