I've been following boxing most of my life, and I have come to the conclusion that selecting the best who ever fought in a division is a matter that - for the most part - is in the eye of the beholder.
It is easier for me to compare fighters from different eras than it is to compare teams or individual athletes in other sports, though, because boxing is largely unchanged since the introduction of gloves. There have been some rule changes, and bouts typically aren't scheduled for as many rounds as they once were, but the length of those rounds hasn't changed, and the ring is the same size as it has been for God knows how long.
In other sports, the equipment has changed - and perhaps the playing surfaces are different. That is especially true, I believe, of baseball, which has seen the introduction of indoor games, artificial turf and protective batting helmets, among other things, as well as changes in rules designed to level the playing field for hitters or pitchers.
Comparatively, boxing is unchanged, and, when you look at Joe Louis' career, it is difficult for any beholder to say that anyone else was better.
Most Americans of the 21st century probably regard Louis as a figure from a bygone era - like Babe Ruth or Jim Thorpe - someone they know only through flickering images on movie screens. If they think of someone breaking racial barriers, they probably think of baseball's Jackie Robinson.
But Louis was more than a barrier buster. The Florida Times-Union writes that Louis, who was born 100 years ago on May 13, was an American hero.
So he was.
Louis didn't break the racial championship barrier in professional boxing's heavyweight division. That distinction belonged to Jack Johnson, the "Galveston Giant" who won the heavyweight title more than a decade before Louis was born and lost it when Louis was a toddler but never really won over white Americans.
(There was more to it, of course - mostly having to do with allegations of Johnson violating the Mann Act, allegations that were clearly racially motivated - but that is a subject for another discussion. My point is, Louis was not the first black heavyweight champ.)
Louis was a popular figure from coast to coast, though, and he was talented. Among the heavyweights of all time, ESPN ranks him behind only Muhammad Ali, just ahead of Johnson and a couple of slots ahead of Rocky Marciano, who knocked Louis out in 1951 in his final fight.
Marciano, of course, is the only heavyweight champion in history to retire undefeated. But when Marciano met Joe Louis in 1951, Louis was 37 years old. Marciano was nearly 10 years his junior. One can only wonder what might have been if they had been the same age when they faced each other.
The year that Louis was 28 (Marciano's age when he fought Louis), Louis successfully defended the heavyweight title twice within a couple of months, winning the first in a one-round knockout, the second in a six-round TKO.
The year before, he defended his title four times - including the famed bout with Billy Conn, the "Fight of the Year" in 1941.
He didn't fight in 1943 or in most of 1944 because he served in World War II, but he experienced a surge in popularity when he was quoted as saying, "We'll win (the war) 'cause we're on God's side."
I've seen several lists that have Louis rated the best heavyweight of all time. That is appropriate, considering that his reign as the heavyweight division's champion was longer than any other.
At times, he was criticized for the quality of his opposition. The lineup of his opponents was known as the "Bum of the Month Club" when he was defending his title (in spite of their nickname, most of those fighters were ranked in the top 10 among heavyweights). But he did face some very good fighters, too, some of the best of his day - Conn (twice), Max Schmeling (twice), Jersey Joe Walcott (twice), Ezzard Charles, James J. Braddock.
In many ways, Louis was produced and presented for mass consumption. His image was tightly managed - he had certain rules he had to live by, one of which was that he could not be photographed with white women - and his handlers were even responsible for coming up with his nickname, the "Brown Bomber."
(Several other nicknames were floated, but "Brown Bomber" seemed to be preferred by most.)
Louis' triumphs in the ring were greeted as symbolic strides for the black community. There weren't many black figures for black Americans to admire in those days, but they didn't admire him just because of his race. He was a heroic figure for all Americans.
"Each time Joe Louis won a fight in those depression years, even before he became champion, thousands of black Americans on relief or W.P.A., and poor, would throng out into the streets all across the land to march and cheer and yell and cry because of Joe's one-man triumphs," wrote noted author Langston Hughes.
"No one else in the United States has ever had such an effect on Negro emotions - or on mine. I marched and cheered and yelled and cried, too."
"What my father did was enable white America to think of him as an American, not as a black," said his son, Joe Jr. "By winning, he became white America's first black hero."
And paved the way for those who followed.