premise: Floyd Mayweather Jr. is boxes competitively.
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 ) . In 2016 , Mayweather was ranked by ESPN as the greatest boxer , pound for pound , of the last 25 years . Many sporting news and boxing websites ranked Mayweather as the best boxer in the world , pound for pound , twice in a span of ten years ; including The Ring , Sports Illustrated , ESPN , BoxRec , Fox Sports , and Yahoo! Sports . He is also regarded as the best defensive boxer in the sport , as well as being the most accurate puncher since the existence of CompuBox , having the highest plus -- minus ratio in recorded boxing history .