Anderson Silva isn't the fastest fighter in the UFC, nor is he its hardest puncher. He doesn't have the best chin, nor is he the organization's strongest man.
But few, if any, fighters in mixed martial arts practice with the kind of attention to detail that Silva pays. It's why he'd stand in front of a wall and repeatedly let someone behind him fire a ball at the wall – just so the ball would rebound directly toward his face.
The ball coming off the wall was meant to mimic punches flying at him. For hours, he'd slip left, slide right, and duck under as the ball whizzed past his face.
"That's why he is so special," lightweight Cristiano Marcello said of Silva, the UFC's middleweight champion. "Other fighters don't think of these kinds of things. But Anderson's desire to be great was so strong and he would work and work to make things just perfect."
It was a simple, but very effective drill for a fighter who wanted to stand in front of an opponent but not get hit very often.
That kind of attention to detail is what has made Silva such a superb fighter and, in the minds of many, the greatest mixed martial artist of all-time.
"I'm always trying to create new things and create new ways to improve myself, so that's one of the training regimens I started back when I was still training Capoeira," Silva said. "It's something I believe helps my reflexes, my quick response and something I can really take into the Octagon."
[Also: Former training partner for Chuck Liddell poised to become big UFC star]
Silva, who faces Stephan Bonnar in a three-round light heavyweight bout in the main event of UFC 153 Saturday at HSBC Arena in Rio de Janeiro, Brazil, is so good because he lets little slip past him.
He's constantly striving to be better, even at 37, even as a millionaire many times over and a sure-fire Hall of Famer.
"He's the greatest fighter of all-time and he does these things like that as if he were just a young kid just starting out," UFC president Dana White said. "A lot of guys could learn a lot from how he goes about things."
Silva is unbeaten in the UFC and has rarely been challenged. That's a rarity in MMA, a sport in which there are so many ways to win and lose that even an outclassed fighter can catch a far more skilled one.
Silva is 32-4 overall in his MMA career and 16-0 in the UFC. He hasn't been beaten since he was disqualified against Yushin Okami in 2006. The last time he was actually beaten came when Ryo Chonan pulled off one of the most spectacular moves in MMA history, catching Silva with a flying scissors heel hook submission on Dec. 31, 2004, in Japan.
His biggest challenge on Saturday will be complacency. Bonnar is only 7-6 in the UFC and hasn't beaten a ranked opponent in his seven years in the UFC.
Silva is an enormous 11-1 favorite in a fight that is all risk and no reward for him. Should he defeat Bonnar in the first round, as he did in two previous forays into the light heavyweight division against James Irvin and Forrest Griffin, it won't matter much. He's expected to crush Bonnar.
But should Bonnar somehow, some way pull off the upset it would be catastrophic for Silva's legacy.
[Related: Anderson Silva's former MMA foes recount facing the G.O.A.T.]
And as meticulous as Silva has been in camp, he understands the nature of the sport. He's a slip at the wrong time away from losing his perfect UFC record.
"That is something that is very unfair, that we could train the most we can, work out a lot and end up making one slight mistake that determines the end of the fight," Silva said.
The one mistake Silva is making these days is the way he is handling questions about fighting light heavyweight champion Jon Jones.
Silva and Jones have lapped the field and are 1-2 in the rankings. Given Jones' Silva-like dominance in the last year at light heavyweight, it makes sense for them to fight each other at some point.
That would make it by far the biggest fight in UFC history. But for some reason that neither man has explained, they aren't interested in fighting each other.
Silva repeatedly has said during Fight Week he won't fight Jones, once calling the chances "impossible" when the topic was broached. Yet, Silva has been open to a potential fight with welterweight champion Georges St-Pierre.
[Also: Nonito Donaire getting inspiration from world-class Bay Area fighters]
His refusal to be willing to even consider a fight with Jones is eye-opening, at the very least. During a conference call last week to promote his fight with Bonnar, Silva may have given a hint as to why he's been so against it, however.
"You know what got me this far is that I'm grounded," Silva said. "My weight class is 185. I'm 37 years old and I feel like I need to be honest to [myself] and continue what I've built, which is to keep defending my belt at 185."
He's clearly coming to the end of the line. Silva isn't going to be another Randy Couture and fight until he's old enough to earn an AARP card.
But Silva recognizes that MMA is one of those sports in which one can never be prepared enough. There is always something new to learn and another problem to solve.
By 37, most fighters have tired of the grind and simply don't have the will or the spirit to push on. Not so with Silva.
"I haven't seen too many guys, if any, like this guy who keep getting better this long into their careers," White said.
Silva is a very physically skilled fighter, but that attention to detail, his thirst for knowledge, is the primary reason he's so good.
Related MMA video from Yahoo! Sports
Other popular content on the Yahoo! network:
• Michael Vick confirms dog is now part of his family
• LeBron James might be adding the skyhook to his offensive repertoire
• Adam Carriker loses bet, dresses up like pro wrestler Goldberg
• Y! Finance: Top 100 places to work in the world