NO. 3 (TIE) ROCKY MARCIANO
Height: 5-10½
Active: 1947-55
Record: 49-0, 43 KOs
Reign(s): 1952-55
Background: Marciano had only an 8½-year career but he sure made a strong impression. The Brockton Blockbuster was known for his uncommon conditioning, resilience and power in spite of his short stature. He fought as light as 178 pounds – which is unthinkable for a heavyweight today – but many of his opponents weren’t much heavier. He had a reach of only 68 inches, one more than Manny Pacquiao. Still, Marciano pounded his way through the heavyweight division and into title contention by the end of the 1940s, which was a quick ascent given that he turned pro in 1947 after learning to box in the Army. He received a shot at heavyweight champion Jersey Joe Walcott in 1952. And he almost blew it. He was behind on points when he landed arguably the biggest punch ever, a right to the jaw that put Walcott to sleep and gave Marciano the belt. He successfully defended six times and then walked away, never having tasted defeat.