Knowing when to walk away remains a fighter's greatest challenge

There will be many who will beg Pat Barry to retire as an active fighter. Antonio Rodrigo Nogueira, too.

Both men were among the most popular mixed martial arts fighters of the last 15 years. They engaged fans with their power and their skill and their love of the sport.

They are great athletes and terrific ambassadors, men who embody everything it means to be a professional.

Fighting, though, is a profession with no forgiveness. When a pitcher can no longer sneak the fastball past hitters on the inside part of the plate, he can use guile to get by. And he faces no serious, long-term medical issues in doing so.

A professional golfer who gets the yips on the putting green faces nothing other than potential embarrassment.

Fighters who no longer have it, however, are an altogether different story. Their lives, literally at risk every time they step into a ring or a cage, are even more in jeopardy.

Much is still to be learned about injuries to the brain, but one thing that has been established beyond a doubt is that a person with a history of concussions is more susceptible to them.

Barry, the charismatic and frequently hilarious former UFC star, was knocked out Saturday in a Glory kickboxing event. It was the third consecutive knockout loss for Barry, following two defeats by TKO in the UFC.

Barry left the UFC because he was a kickboxer and tired of trying to learn wrestling and grappling and those things that make one a successful MMA fighter.

Barry was knocked out in three of his last four MMA fights and now in a kickboxing event. He's so fearless and aggressive and eager to please – to score a devastating KO himself – that he leaves himself vulnerable and regularly has been knocked silly.

This isn't good for his long-term health, clearly. No fighting sport is "safe," and there is considerable risk involved. But part of the appeal of the sport, both for the spectators and, in a lot of cases, the competitors, is seeing them deal with that risk.

It's why people watch others walk a tight rope with no safety net below, or why decades ago Evel Knievel became a cult figure in the U.S. by trying all sorts of risky ventures.

A grappling match is far safer for those involved than a slugfest that ends with a violent knockout, but the public doesn't care for them nearly as much and often boos loudly when a fight hits the ground. That's frequently true even when the ground battle is captivating.

A fighter like Barry is beloved because of his willingness to take and deliver concussive blows, consequences be damned, for the sake of entertainment. The fact that he's a clever, witty guy who doesn't take himself too seriously simply increases his appeal.

Many of his fans will chastise anyone who urges him to retire, who dares to tell him that he's had enough.

The same is true for fans of Nogueira, who was knocked out last month in Abu Dhabi by Roy Nelson and now has been viciously knocked out three times in his last eight bouts.

No one can tell someone else to retire. But there is a check and balance in team sports that fails to exist in fighting. Football players who can't produce any longer are put on waivers and left to look for work. For a while, there's often someone willing to give a second, third and even fourth chance, but at the end of the day, performance forces the athlete to make career decisions.

There's always some promoter somewhere, though, who will give a fighter another bout.

The final act of so many fighters is not good. Superstar boxer Floyd Mayweather Jr. was ducking a question on Saturday when he discussed fighter safety, but the point he made was valid and cannot be ignored.

"The thing is this: I have a life after boxing," Mayweather said Saturday after his win over Marcos Maidana in response to a query by Yahoo Sports. "He has a life after boxing. This is already a brutal sport. Of course we're here to please the fans, but what about our health when boxing is over?

"Half of the boxers who are in the fight game now can't articulate well. So do we care about the fighters' health? You're always asking the questions, 'Why did this guy die? Why is he in the hospital? Why did he lose all his money?' "

The risks of fighting are great, even under the best of circumstances. But when fighters are aging and beginning to repeatedly get knocked out, the risk increases exponentially: The more knockouts, the more serious the risk in the next outing.

Retirement or so-called farewell fights should also be outlawed, because if a fighter isn't fit to compete, then it makes no sense to go out and get kicked and punched in the head again in order to say goodbye.

Many fight on because they have no other source of income and have no idea what else to do with their lives. Fighting is all they know.

Neither Barry nor Nogueira will be forced to retire, no matter how much some may urge them.

They'll have to decide that for themselves.

Hopefully, they have the ability to assess their situations in a clear-headed, responsible manner.

If they don't have that ability, it's already way too late.

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