Floyd Mayweather Jr.

Floyd Mayweather Jr. retired with a perfect 50-0 record, including 27 knockouts, making him the only world champion to retire undefeated across five weight divisions. His technical mastery and defensive genius resulted in a 0.1% opponent punch accuracy rate in his prime, virtually untouchable. This record outperforms #10 Manny Pacquiao's 62-8-2 mark, as Mayweather maintained perfection over 50 fights. His 2015 super-fight against Pacquiao generated 4.6 million pay-per-view buys, shattering all previous records at the time and cementing his status as a generational talent.