premise: Floyd Mayweather Jr. is a professional beat boxer.
hypothesis: Floyd Joy Mayweather Jr. ( born Floyd Joy Sinclair ; February 24 , 1977 ) is an American former professional boxer who competed from 1996 to 2015 , and currently works as a boxing promoter . Widely considered to be one of the greatest boxers of all time , undefeated as a professional , and a five-division world champion , Mayweather won fifteen world titles and the lineal championship in four different weight classes ( twice at welterweight ) .