It’s been a different Floyd Mayweather Jr. this week

LAS VEGAS — A big mistake while pondering Floyd Mayweather Jr. is to try to make sense of him. His unpredictability is his only certainty.

It is well before noon Friday at the MGM Grand. This is not so much a resort and casino as it is a massive enclosed labyrinth of contrasts. Under the same roof, yet miles apart, unemployed dads lose the rent money to slot machines while Mayweather generates a throng of worshippers that symbolizes why he will increase his already hefty bank account by about $32 million.

The weigh-in for the Mayweather-Miguel Cotto boxing match is still three hours away, but the line to see it snakes down hallways and past stores. It is a quarter mile of humanity that apparently has no life or way too much time on its hands. The reward for this several hours of time lost forever will be to watch men stand on a scale in their underwear.

Has our current celebrity-starved society completely lost it? Admission was free, but the real price must be some internal sense of diminished self-worth.

Then again, maybe not. Maybe that is the same as trying to figure out Mayweather by applying sociology.

Because Mayweather is fighting against the rock-jawed, quietly powerful Cotto in the MGM Grand’s Garden Arena on Saturday night, his long-running saga rises up once again in the public domain. He has never been beaten in a professional boxing ring, nor has he been particularly beloved while getting to that 42-0 he so cherishes.

As a child in Grand Rapids, Mich., his boxer father once refused to release the grip he had on him while a man pointed a gun at Floyd Sr.’s head. Father knew best, reasoning correctly that his brother-in-law would not shoot him in the head with a baby in his arms. Floyd Sr. got shot in the leg, and Floyd Jr. got a valuable lesson: First, you first take care of No. 1. Yourself.

Each fight promotion takes on its own character. In this one Mayweather has been restrained, mellow, almost humble. That is way out of character.

The braggadocio that is standard fare has been replaced by an almost serene presence. He has praised Cotto more than any other opponent and he has even taken to paying homage, on a daily basis, to his archenemies, the purveyors of his gangsta-rap, I’m-better-than-all-you-pathetic-jerks image. That would be the media.

“I want to thank the media for keeping me relevant,” he has said, day after day. After a while, you start thinking he might actually believe it.

Mayweather is as impossible to like as he is to completely dislike. In a crowd, with cameras rolling, he struts and swaggers. One-on-one, he can be engaging, analytical, friendly.

But there are even exceptions to that.

In an interview session with a handful of writers here Tuesday, Mayweather was doing his good-guy routine until Associated Press columnist Tim Dahlberg, one who suffers no fools, brought up the subject of the apparent dead-in-the-water fight against Manny Pacquiao. Pacquiao represents the only real challenge to Mayweather’s boxing supremacy and ego, not necessarily in that order.

Mayweather responded with a back-to-the-good-old-days Mayweather rant that covered everything from politics to patriotism, as well as how much Pacquiao’s head had grown, making him an obvious drug cheat. There is, of course, an ongoing slander suit on this topic, brought by Pacquiao against Mayweather, but legal tangles have never slowed Mayweather.

During the rant, Mayweather said of Bob Arum, Pacquiao’s promoter, with whom he would have to do business were the two superstars ever to get in the ring: “Arum, he’s a lawyer, so we already know he’s a professional liar.”

Later, Mayweather said he wasn’t ranting, “just speaking my mind.”

Dahlberg, who wrote that Mayweather eventually offered his hand and said, “Have a nice day,” also called the ever-present Mayweather entourage “a band of sycophants.”

The Mayweather entourage is well known for never sneaking quietly through the back door of various casinos and nightclubs here. An auto dealer told a reporter here Thursday that he “disliked Mayweather” because every time he shops for a car, he brings the whole crew with him, disrupts the business for hours and often returns three and four times before buying.

With Mayweather, the ebbs and flows are inexplicable, often contradictory.

When he fought, and beat, Diego Corrales here in January 2001, he made a point of publicly stating that he was fighting Corrales “on behalf of all victims of domestic abuse.” That was a non-boxing jab at Corrales, who went to jail shortly after the fight, having been convicted of beating his pregnant wife, Maria.

Mayweather, of course, will begin his own jail time June 1 for a similar conviction.

Part of Mayweather’s current split personality most likely has to do with the bulk of the promotional load falling on him. Any advance noise for this one has come from Mayweather, who knows how to sell almost as well as he knows how to punch. Cotto, quiet and struggling with English, has done the minimum.

That is a particular challenge for Mayweather, because the pay-per-view price is an outrageous $69.95, prompting one writer to ask, rhetorically, if Joe Louis were fighting Rocky Marciano.

Often lost in all this, but not to the likes of veteran fight promoter Don Chargin, is that Mayweather’s hands and feet are still faster than his mouth, which is saying something.

“The other stuff always gets in the way,” Chargin said Friday, “of what a great fighter Mayweather is.”

bill.dwyre@latimes.com