Floyd Joy Mayweather, Jr. (born Floyd Sinclair on February 24, 1977), is an American professional. He is the son of Floyd Mayweather, Sr.
From July 18, 2005 through June 2, 2008 he was rated by The Ring magazine as the number-one pound for pound boxer in the world. Mayweather has won six world boxing championships in five different boxing weight classes; he is the former WBC welterweight champion, a title he vacated upon his retirement. He was named Ring Magazine Fighter of the Year in 1998 and 2007.
Mayweather is undefeated with 40 wins including 25 by knockout.
Source : Wikipedia.com