Does an undefeated record make Marciano the true GOAT, or is there more to greatness? April 27, 1956 — Rocky Marciano hung up the gloves at a perfect 49-0. No rematch. No comeback. No blemishes. The only heavyweight champion to retire undefeated. #RockyMarciano #BoxingLegends #ClassicBoxing #OldSchoolBoxing #BoxingGreats #BoxingGOAT