Floyd Mayweather Jr. uses boxing smarts to outmaneuver opponents

The smallest detail is never far from Floyd Mayweather Jr.’s mind. It has allowed him to compile a bank account that exceeds $100 million, a testament to the fighter’s brilliance.

“I once introduced him to a guy I knew, and just the other day, six years later, Floyd saw the guy in a crowd and said, ‘Hey, there’s your friend,’ ” said Nate Jones, Mayweather Jr.’s close friend and assistant trainer.

“This guy remembers things like an elephant.”

That brain power is constantly working for Mayweather (44-0, 26 knockouts), who relies on it for mental pre-fight games and to out-smart opponents in the ring.

Sure, rapid footwork, punching speed and defensive skill help make Mayweather, 36, the world’s top pound-for-pound fighter. But it’s his quick, productive thinking that could be the decisive factor when he fights Saturday night against younger, stronger, bigger junior-middleweight world champion Saul “Canelo” Alvarez of Mexico at MGM Grand in Las Vegas.

“This fight can go one of two ways,” Mayweather said recently after a workout at his Las Vegas gym. “He can come fight hard, and we’ll see how that plays out. Or he can try to match me skill for skill. And we’ll see how that plays out. You know me. I can do it all.”

Some of his biggest fights since 2007 have shown that.

In his breakthrough victory that year, a split-decision over Oscar De La Hoya, Mayweather worked to get the veteran off his game by wearing the green and red colors of Mexico into the ring, complete with a sombrero, insulting De La Hoya, who was counting on the festive spirit of Cinco de Mayo to lift him to triumph.

“Wearing the sombrero … he does things like that, that’s his game plan, to beat you by hoping you change your game plan and strategy,” De La Hoya said recently at Alvarez’s training home in Big Bear Lake, where he warned the 23-year-old of such tricks. “My strategy went out the window once that bell rang because I wanted to knock his head off so badly.”

Three years after that, Mayweather found himself in perhaps the most perilous moment of his career after enduring a knee-buckling right hand to the jaw delivered by Shane Mosley in the second round of their fight.

“No matter what they can do, I can adjust, always,” Mayweather said. “I gave Shane a certain look after he hit me, a look he knew — ‘strong, huh?’ He had hit me, I said, ‘Good shot, comes with the territory.’ I told him, ‘I’m willing to die. Are you?’ ”

The fight changed at that moment. Mosley could never find another opening, and began tiring.

“I hit him with a good body shot and it was all backing up from there,” Mayweather said of his unanimous-decision triumph.

Then came the 2011 fourth-round knockout, or sucker punch, of Victor Ortiz.

“The guy was missing shots, got frustrated and he head-butted me, knocked a hole in my lip,” Mayweather said. “That got me upset.”

At that point, Mayweather had been fighting professionally for 15 years after being raised in a boxing gym by his boxer father and uncle and participating in the 1996 Olympics.

If there’s a trick in the book to be played, Mayweather has seen it, knows it or has thought of it. His anger generated masterful instant recall.

As Ortiz overcompensated for his cheap shot by kissing Mayweather on the cheek and repeatedly apologizing and asking to touch gloves to show there were no hard feelings, Mayweather’s mind was racing, waiting for the instant referee Joe Cortez called for the fight to resume.

As soon as Mayweather heard it, even though Ortiz wasn’t looking, he let loose a hard left to the youngster’s face accompanied by a look of retribution, followed by a more powerful right to the jaw that ended the fight.

Then, on Mayweather’s terms, Ortiz was officially sorry.

“There’s no fighter mentally stronger than me,” Mayweather said. “If it was chess, you could have 12 pieces on your side and I could have one, and I’d still win.”

When he goaded quiet Miguel Cotto into trash talking last year, Mayweather reasoned, “He’s not a trash talker. I got him. He’s a beat fighter.”

For Alvarez (42-0-1, 30 KOs), Mayweather has poked at doubts that may creep into the psyche of a young man preparing for the biggest fight of his career.

Mayweather’s camp has insulted the Alvarez camp for compromising to allow for a catchweight limit of 152 pounds in the 154-pound division, and stories have emerged that a double agent has infiltrated the Alvarez camp to pass on inside training information to Mayweather.

“I’m not saying he’s not a good fighter, not a good competitor,” Mayweather said of Alvarez. “He’s strong, can punch hard.

“But I’ve faced every style there can be. I’m not worried about anything. Nothing. I don’t get nervous. I was born to do this, born to be put in this position. I’ve been here so long. A lot of other fighters get nervous. Is ‘Canelo’ nervous? Absolutely. This is different, this is the pinnacle. This is not the undercard to my fight like he’s fought before. This is Mayweather.”

As they toured 11 cities together hyping the fight, Mayweather said he could see that uncertainty in Alvarez.

“I can look in guys’ eyes and tell,” he said.

“I can box and fight on the inside. I can counterpunch, can use my legs and go both ways. I can turn it into a dirty fight. Whatever. When it’s all said and done, I can always find a way to win. I was born to win and I’ll die a winner. No matter how you get the victory, as long as you get it. People always remember winners.”

lance.pugmire@latimes.com

Twitter: @latimespugmire