Whether it's after losing a close decision or being on the receiving end of a sustained beating, some can just dust themselves off and fight another day.

But some fighters just do not know when enough is enough.

In this column last week, I discussed the third and what looks to be the final battle between welterweights Brandon Rios and Mike Alvarado.

It promised fireworks and it certainly did deliver - but not in the way many fans hoped.

Alvarado looked a husk of the fighter he once was, enduring a three-round hammering in his hometown of Denver, Colorado last Saturday at the hands of his younger, fresher opponent. Rios looked almost surprised as he battered his 34-year-old foe with such ease, dropping him in the second round.

After failing to rise from his stool for the fourth round, Alvarado all but ended his career as a prizefighter.

I hope he calls it quits but I can't see it happening.

Fighters have too much pride, too much heart to even contemplate the notion of bowing out with a defeat.

Some of the greatest fighters to ever grace the squared circle have put their legacies on the line by battling on to the bitter end.

Had Mike Tyson retired in 1988 after his destruction of Michael Spinks, he'd probably be recognised as the greatest heavyweight of all time. If he'd quit after being decimated by Lennox Lewis in 2002, it would have been a sad curtain call for a once unstoppable force.

But no, "Iron" Mike chose to fight on. After being knocked out in four by British veteran Danny Williams (another retirement-dodging warrior) in 2004, Tyson was sparked a year later by Irishman Kevin McBride. The Tyson of old would have ate them for breakfast.

Some of the true greats of yesteryear continue to trundle on as desperate, Harlem Globetrotter-esque sideshows, struggling against virtual nonentities.

Roy Jones Jr should have retired after being crushed by Antonio Tarver in 2004. But instead the former four-weight world champion is now reduced to fighting journeymen in Latvia (no joke). Jones' former bitter rival James Toney, now 46, continues to plunder on in the heavyweight division and last fought in Prizefighter at York Hall in November 2013.

But Jones is not alone in his journey through the boxing wilderness.

Heavyweight great Evander Holyfield fought until 2011, 25 years since his first world title fight in 1986. A Sugar Ray Leonard suffered the first knockout of his career at age 40 in 1997 after a five-year absense. Roberto Duran, Julio Cesar Chavez, Terry Norris all showed their age and battle scars in later bouts.

But undoubtedly the most depressing of all was Muhammad Ali's last two outings in the ring. The Greatest was nothing more than a punching bag for Larry Holmes, who after disposing of Ali in 10 rounds, shed buckets of tears for brutalising his defenseless idol.

So hopefully Mike Alvarado will take a look back at some of his heroes who left the ring in dejection rather than shrined in glory.​