For all the great things he did in his boxing career, George Foreman dealt the sport a serious blow when he won the heavyweight championship at age 45 in 1994 by knocking out Michael Moorer.
Foreman's success helped create an entire class of fighters who felt that they, too, could fight and be successful after 40. Only Bernard Hopkins, who in 2011 broke Foreman's record as the oldest man to win a major world title when he defeated Jean Pascal at age 46, has had any kind of consistent success over 40 against top fighters.
The latest to give it a shot will be Shane Mosley, a one-time lightweight, welterweight and super welterweight champion who turned 40 in September. On May 5, Mosley will meet 21-year-old Saul "Canelo" Alvarez at the MGM Grand in Las Vegas.
Mosley was horrendous in 2010 and 2011, getting routed by Floyd Mayweather Jr. and Manny Pacquiao and fighting to an uninspired draw with Sergio Mora in between.
Alvarez had just turned 7 when Mosley won his first world title Aug. 2, 1997. Now, Alvarez is 21 and a heavy favorite to retain his belt. Mosley said on a conference call last week he's fueled by those who doubt him.
"The haters are what keep me motivated," Mosley said. "Domination is on my mind. I want to be the best I can be and showcase my strengths."
Other than Foreman and Hopkins, though, few boxers in the last 20 years have had any significant, sustained success beyond 40. Former undisputed heavyweight champion Evander Holyfield, who at 49 is still not retired, has gone 6-5 post-40 and was beaten by the likes of Larry Donald and Sultan Ibragimov.
Larry Holmes, one of the four greatest heavyweights ever, was 21-3 after 40, but only had one significant win, a 1992 victory over Ray Mercer. Other than that, Holmes either beat a collection of third-rate fighters or lost.
In the pre-Foreman era, even the greatest fighter didn't have real success after 40. Sugar Ray Robinson fought 44 times after his 40th birthday and went 30-10-3 with one no-contest, but none of the wins could be counted as significant.
The odds are heavily against Mosley, who in his prime would have been a massive favorite to defeat Alvarez. Mosley's excuse for his poor recent performances was not his age but what he said were injuries that prevented him from preparing.
He insists, though, that he's healthy and will shock the critics. They all say that, but Mosley said the wisdom he's gained in 18 years as a pro, spanning 55 bouts, will serve him well.
"Basically, I'm able to change and I'm able to do things that I couldn't do in other camps," Mosley said. "I'm able to do a lot more. I can run more. I can move better. I can slip and slide. I can punch harder. I can just do more things."
The eye test tells a different story. Mosley at 25 was a beast. Mosley at 40 looks like an old guy hanging around for one more payday.
Hopefully, he'll prove the doubters wrong, but boxing is a serious endeavor. As ex-world champion James Toney often says, you play golf, but you don't play boxing. Hopefully, if Mosley turns in an effort similar to what he did in the previous two years, he'll grasp that and start the countdown for his induction into the International Boxing Hall of Fame.