evidence: Marvelous Marvin Hagler (born Marvin Nathaniel Hagler; May 23, 1954 – March 13, 2021)[2] was an American professional boxer. He competed in boxing from 1973 to 1987 and reigned as the undisputed champion of the middleweight division from 1980 to 1987,[3] making twelve successful title defenses, all but one by knockout.[4][5][6][7][8][9] Hagler also holds the highest knockout percentage of all undisputed middleweight champions at 78 percent. His undisputed middleweight championship reign of six years and seven months is the second-longest active reign of the 20th century.[10] He holds the record for the sixth longest reign as champion in middleweight history.[11] Nicknamed "Marvelous" and annoyed that network announcers often did not refer to him as such, Hagler legally changed his name to "Marvelous Marvin Hagler" in 1982.[12] [...] - ^ "Marvelous Marvin Hagler, Boxing Legend And Brockton Native, Dies At Age 66". March 13, 2021. Retrieved November 12, 2021. [...] - ^ Fauzia, Miriam (March 13, 2021). "Fact check: Boxing champ Marvin Hagler's death not caused by COVID-19 vaccine". USA TODAY, a division of Gannett Satellite Information Network, LLC.