The volatility that defines Floyd Mayweather Jr. is rooted partly in the complex relationship with his father.
In June, 2012, Mayweather Jr. reported to Clark County (Nev.) jail to begin serving what would end up as 60 days of a 90-day sentence for a battery domestic violence conviction against the mother of his three children.
A legacy of household unrest dates to Mayweather's childhood.
Mayweather Sr., who in 1978 fought and lost to Sugar Ray Leonard, told the story of a day in their Grand Rapids, Mich., home when he picked up his crying toddler son from a walker. A few minutes earlier the dad had put his hands around the throat of Tony Sinclair, the late brother of Mayweather Jr.'s mother, who had overstayed his welcome living in their home, according to Mayweather Sr.
Sinclair went outside to get a rifle, kicked in a door to the house and aimed the barrel at Mayweather Sr.'s face while he held his son.
"If you're going to kill me, you're going to kill the baby, too," Mayweather Sr. said he told Sinclair. "[Floyd Jr.'s] mother said, 'Give me the baby.' She was pulling the baby out of my arms so her brother could shoot me.
"But I wasn't going to put that baby down. I didn't want to die. It wasn't about putting my son in the line of fire. I knew [Sinclair] wouldn't shoot the baby. So he took the gun off my face, lowered it to my leg and bam!"
Mayweather Sr. lifted his left pant leg to reveal the grotesque damage caused by the blast.
"I used my mind that day," Mayweather Sr. said, "and the first thing on my mind was, 'Ain't nobody getting killed.' "
With that scene as a starting point, the quest to make sense of the complexities and contradictions of Mayweather Jr.'s life makes him as evasive to dime store psychology as he is to foes in the ring.
The unbeaten champion, with his retinue of bodyguards, is as likely to be hot tempered as he is generous. He quietly paid for a cancer-stricken former opponent's funeral, and gave the mother of a sick girl $40,000 for a medical bill.
"There's only so much you can buy," Mayweather Jr. said.
In the calm inside his Las Vegas gym in 2012, Mayweather reflected on his place in the world.
"The last time I checked, this is what the American dream is," Mayweather said. "Who doesn't want to be rich, and make this kind of money? They told me when I was growing up that dreams come true. I dreamed it, and made it happen.
"There's two sides to every person. There are some other athletes who portray a certain image and talk a certain way like they're this great person, but then the truth comes out," he said. "Everyone's not the same, so don't sit and try and judge me for how I've done it."
On that day, Mayweather Sr. returned to his son's gym for the first time since their infamous blowup caught by television cameras the year before, when Mayweather Jr. kicked his father out of the building, firing a barrage of expletives.
"My dad used me as a shield to a gun; I never had a stable home," Mayweather Jr. said. "My mom did drugs. My dad tried to live his career through me. Then he went to prison [for selling drugs].
"Once I got old enough to pay my own bills, I let him know I didn't need him anymore. ... The main thing I learned was to believe in yourself. You have to. Because no one else will."
The mediator to the family drama is the boxing champion's uncle and trainer, Roger Mayweather.
"My brother taught Floyd the gift of boxing," Roger Mayweather said. "This is what my nephew was born to do.
"There are certain things a father does for his child to show that he loves him. And whatever gifts Floyd got from his father when he was young, he is fighting on those gifts today."
Before each training camp, Mayweather Jr. envisions being poor again, living at his grandmother's small home, said Nate Jones, a childhood friend from Michigan who serves as an assistant trainer.
It's a transformation, Jones said, fueled by an intense fear of losing.
"I was at Floyd's house about six years ago -- he didn't even have a fight scheduled -- and he woke up in tears," Jones said.
"I lost last night," Mayweather told his friend.
"You're crazy, boy," Jones replied. "You was dreaming."
Minutes later, Jones couldn't find Mayweather. More than an hour later, the fighter returned, informing Jones he had gone for a 10-mile run.
"This is a person who understands you can have anything or nothing in life, that anything can happen to you," Jones said. "You can make millions. Be broke. Or be in jail."
In the domestic violence criminal case, Mayweather allegedly threatened to kill his ex-girlfriend, Josie Harris, pulled her hair and threw her to the floor at her home. The Clark County criminal complaint alleged Mayweather Jr. told Harris he would make her and her new boyfriend "disappear."
Felony coercion counts were filed, alleging Mayweather Jr. threatened to beat his two sons if they left the residence or called 911 during his verbal and physical attack of Harris.
In December, 2011, Mayweather pleaded guilty to one domestic violence charge and no-contest to two harassment charges.
It was a day of reckoning.
"You take the good with the bad and the bad with the good -- that's life," Mayweather said. "You live and learn. The only thing [jail] will do is make me mentally stronger."
And on the afternoon his father visited the gym, Mayweather extended his hand for a shake and offered a quick embrace.
"At the end of the day, there's no hatred," Mayweather Sr. said. "He's my blood, my son and the apple don't fall too far from the tree."
"I'm good for anything that's put in my way," his son said.
(A version of this story first appeared in the Times in May, 2012.)