By most historical counts, Joe Louis is reckoned as the top boxer of the 1940s. That's the way it is when you are the dominant heavyweight champion of the world. 

But based on what was accomplished in the ring, Sugar Ray Robinson was probably the fighter of the decade for the 1940s. He was probably the fighter of the decade for the 1950s, too. 

His best unbeaten streak spanned both decades. After starting his career 40-0, Robinson suffered his first loss against the Bronx Bull, Jake LaMotta, in February 1943.

After that, he won 88 fights without a loss before getting upset by Randy Turpin in July 1951. During that streak, Robinson collected first the welterweight and then the middleweight world titles. 

After suffering his second loss against Turpin, Robinson came back two months later and knocked the Englishman out in the rematch.

Robinson started 1952 by beating Bobo Olson by decision in March and then knocking out Rocky Graziano a month later in April.

In June 1952, he collapsed in the 104-degree heat in Yankee Stadium against light heavyweight world champion Joey Maxim, in a fight where he was far ahead on the cards.

That's the stuff a pound-for-pound resume is made of.