On this day in 1956 Rocky Marciano announced he was retiring from boxing. He had turned professional in 1947 and retired with a record of 49-0-0. He had won the World Heavyweight Championship in 1952 and retired as champ. He remains the only Heavyweight Champion to retire undefeated. He had the good judgment also to stay retired. Not knocking Marciano he was a great champion but I don’t think he ranks in the Top 5 Heavyweights Champions of All Times. Muhammad Ali and Joe Louis have to rank at the top. Jack Johnson, Jack Dempsey and Smokin’ Joe Frazier round out my Top 5ive. Marciano would die at the age of 45 in a plane crash in 1969.