CHARLOTTE — Ron Rivera sat in on a positional meeting as he watched one of his Carolina Panthers assistant coaches dress down the players. The assistant had given his players a written exam to make sure they fully understood their assignments and the team’s gameplan. The players only filled out the parts of the test they thought applied to them.

“Where’s Page 4?” the coach asked one player. He shrugged.

“Where Page 1?” the coach asked another. It wasn’t done.

“You guys are starters!” the coach screamed. “And you didn’t even fill out the whole test. What kind of example does that set? You let your teammates down! You took the easy road!” He made other such points with the usual enthusiasm and vigor of an assistant football coach.

Rivera watched all this quietly. In moments like these, he can look more like a professor of poetry pondering Yeats than a football coach and one-time member of the Chicago Bears. Have you seen him on the sideline? Stoic. Placid. Rivera got up to leave, but the coach stopped him and asked if he had anything to add. Rivera paused as if considering something.

“Yeah, I’ve got something to say,” Rivera said, and then he looked at the players. “Let me tell you guys something. Last September, when we started, I showed you a picture of my house after the fire. You remember that? Let’s me tell you, a house fire, it’s traumatic. It impacts you. It changes you.

“You know what happens after a house fire? They bring in lawyers. They bring in the fire investigators. They bring in the police. And they all start questioning you. They ask about your personal finances. They ask if anybody is out to get you. They ask if you are out to get anybody. It’s personal. They break you down.

“Then we go inside the house. And I’m looking at the fireplace. I have a family nickname. My kids call me Mr. Safety. My whole life — and I get this from my father — before I go to bed, I check the house. That’s what I did before I went to bed that night. And, still, we had a house fire. So I’m looking at the fireplace, and a detective comes up to me and says, ‘I know what you’re thinking. And you need to stop thinking that. You could not have prevented this.’

“And then, do you know what he said to me? He looked around at my house, at all the damage. And he looked at me and said, ‘This happened because somebody did not do their job.”

And with that, Ron Rivera left the room.

* * *

Ron Rivera cannot remember if he has interviewed for nine or 11 NFL head coaching jobs. The newspaper clippings say it was nine interviews, and that might be right, but Rivera wonders if the reporters missed a couple. It sure felt like 11. Well, wait, he can tell you exactly how many interviews because he has kept all the notes. Rivera keeps everything — notes, lists, scribbled goals, mission statements. He likes to look through his life now and again so he can remember exactly how things happened. Rivera does not like imprecision.

He looks through some files, but before he comes across his interview notes, he sees something even more precious: The color-coded notes he took after his first heart-to-heart conversation with Hall of Fame coach John Madden. Oh, yes, these are special. This conversation changed his life.

Think of Ron Rivera as you see him now. What do you see? He’s the coach of the Carolina Panthers, who just finished the regular season 15-1 — the best record in the NFL in four seasons. His Twitter handle is @RiverboatRonHC, and his team plays loose and free and celebrates out loud. Quarterback Cam Newton is a singular presence, the defense is spearheaded by linebackers Luke Kuechly and Thomas Davis and the players swear by him.

“Coach Rivera inspires us to be better in every part of our lives,” Newton says.

Well let’s be honest: Everybody in North Carolina loves Rivera.

“How he has built his program and the culture that he has developed there,” Duke coach Mike Krzyzewski says, “makes everybody want to pull for him.”

Now think of Ron Rivera and how he looked three years ago, at the end of the 2012 season. The Panthers had finished their third straight losing season, two under Rivera. The offense and defense were equally mediocre — both ranked 18th in the NFL — and at one point Carolina had lost four straight games by a total of 10 points. NFL Network, among others, reported on the last day of the year that Rivera would be fired and, what’s more, he knew it was coming.

“It isn’t true,” Rivera says now. “It never was true. I always had optimism. I always had hope.”

His hope came from something owner Jerry Richardson had told him during that season. He said, “Ron, don’t worry about what anybody says. Nothing is going to happen during the season. Don’t look over your shoulder. You just do your job, and at the end of the year, we’ll talk about the season and the future. I want you to concentrate on making sure that the team is getting better.”

Rivera believed (wanted to believe?) that the team’s end-of-the-year improvement — four straight wins during which the offense averaged 31 points a game — would earn him another year as coach. That’s what happened. But Rivera does not deny that he was at a low point. He’d wanted this job for so long. For decades. He could remember vividly being a rookie linebacker on the 1984 Chicago Bears, a defense already developing into the greatest he ever expects to see. He heard the growl of defensive coordinator Buddy Ryan.

“Chico!” Ryan shouted. They all called him “Chico” because he was the first man of Puerto Rican and Mexican descent to play in the NFL, and the nickname was the pro football way of recognizing the pioneering achievement.

“Chico,” Ryan shouted, “Get your ass over here. Stand here next to me.”

For a few plays, Ryan was quiet. And then, suddenly, he started unleashing questions.

“What’s the formation?”

“Pro nine.”

“WHY?”

“They’re a bootleg team, and you want to make sure the linebacker is keeping contain.”

A pause.

“What’s the defense, Chico?”

“Samurai.”

“WHY?”

“You want to blitz up the middle because the backs are releasing outside.”

The questioning went on and on. Buddy Ryan probably didn’t know (or possibly care) that he was triggering the mind of a football coach. He just wanted to be sure his middle linebacker knew his assignments. But in those rough exchanges, Rivera saw his future. He loved this game. He loved the punch and counterpunch, loved the way a coach could help players feed off each other, loved the never-ending quest for perfection. Yes, he wanted to be a coach.

He studied. He talked to people. He read leadership books. Most of all, he watched how the great coaches worked. He was in awe of how Bears coach Mike Ditka galvanized his teams. “I remember one time he was so mad at us for the way we started practice,” Rivera says, “he just said, ‘That’s it. We’re done. Let’s go. Practice is over.’ And he just walked off.

“Well, what happened? We stayed, and we practiced. Mike Singletary grabbed one of the scripts, and we practiced right off the scripts. That was what made Mike so good. He made us take ownership of the team.”

Jim Johnson was different. Johnson was a legendary defensive coordinator, one of the best in NFL history. When Rivera became the Eagles’ linebackers coach, Johnson called him into the office.

MORE: Should Cam or Wilson be MVP? | PFT Divisional Picks: Panthers or Seahawks?

“Now listen,” Rivera remembers Johnson saying. “You have the hardest job on the defense. I’m an old linebacker coach. I’m going to come into your meetings, and I’m going to take over your meetings. I’m going to take over your drills. Just don’t be offended.”

Rivera nodded, but for the next few months of offseason football, he found Johnson to be fantastic and open and not at all controlling. Rivera was always good with computers, so he became Johnson’s tech advisor as well as linebackers coach. It was all going so well until the first practice started.

“Our very first drill, we’re running a blitz,” Rivera says. “Jeremiah Trotter was our middle linebacker, and he loops outside. All of a sudden it was like (Johnson) turned his head around and threw up green puke. He just started cussing, “You (bleepers), run it THIS way! This is how you do it (bleepers!) If I ever (bleeping) see …’ I’m like going, ‘Who is this dude?’ But it was his way of making sure everyone understood how important it was that everything, everything is tight.”

Rivera put that in his coach’s notebook too. Andy Reid got into everything. Noted. Dave Wannstedt let people do their own thing. Noted. Buddy Ryan, well, he was a sergeant in Korea, and he coached that way. Noted. Rivera’s father, Eugenio, a military man and as disciplined as anyone Ron would ever know, reminded him that you “dress the part to be the part.” Rivera would always make sure he was dressed immaculately when meeting with people.

Yes, he would be ready when he was finally given that head coaching job. Then after all those interviews and all the notes and all that work, he was given the job. And two years in, he realized something: He wasn’t ready at all.

“Ron,” Jerry Richardson told him on that day in 2012 when everyone thought Rivera would get fired, “we’re going to stick with you because we believe in you.”

And then he said: “I want you to talk with my friend John Madden.”

AP Photo

These days, Ron Rivera has a small office downstairs next to the team’s locker room. He didn’t have this office three years ago because back then he didn’t believe a football coach should spend time in the locker room. It’s the players’ locker room. It’s their sanctuary. Coaches out.

But after his near-miss firing in 2012, Rivera realized he needed to reevaluate everything. He asked several of the team’s key players to go to dinner — wives, girlfriends, family, the whole bit. When dinner was over, he and the players moved to a room, and he asked them to tell him what had gone wrong during the season. They hemmed and hawed for a while, but when they realized that Rivera was serious they unleashed complaint after complaint — about this player, about that coach, about this team rule, about everything. Rivera’s head spun. He had known about none of it.

“Wait a minute,” Rivera finally shouted. “Why didn’t you tell me all this before?”

The players shrugged. They didn’t want to be snitches. They didn’t think he’d care. They didn’t think he’d do anything about it. Rivera was fuming. He’d made it entirely clear to his players — or so he thought — that his door was open, and he EXPECTED them to come to with any complaint or information or idea that could help or hurt the team. They had not come.

“How do you find out what’s happening with your team?” he asked Madden in their engrossing conversation about football. The type-written notes from the discussion cover many pages and many topics: how to deal with adversity; how to keep teams together; what positions matter most in the new NFL. Madden, of course, won a Super Bowl with the Oakland Raiders, and he’d become an iconic broadcaster and the face of the video game that shaped the football minds of countless millions. What Rivera found was that Madden has a singular ability to pierce through nonsense and get to what matters.

“The biggest mistake I see with coaches,” Madden said, “is that they aren’t themselves. You have to be yourself, or it won’t work. And then, you get fired, and you have to live with the regret that you didn’t give it your best shot because you weren’t yourself.”

Then Madden said something that changed everything for Rivera.

“You hear all the time about coaching by the book,” Madden told him. “Right? You hear that all time, don’t you? He coached by the book. He should have gone by the book. Ron, here’s the secret. There is no book.”

There is no book. If Ron Rivera was ever to write his own story, that might be the title. There is no book. It was like a veil lifted, and Rivera saw things clearly for the first time. The countless guidelines he had learned through the years? They are just guidelines. The unwritten rules that coaches follow? They are only suggestions. Rivera didn’t have to follow the precise path of the people he admired. He didn’t have to be the coach he had visualized. There is no book.

So Rivera had this office built downstairs and determined that he would spend as much time in the locker room as he could. He would engage his players, study them while they interacted with each other, learn as much as he could about their personalities. It was true that his own coaches had not done it that way. Doesn’t matter. There is no book.

He decided that he would no longer worry about what he was wearing. It wasn’t that he doubted his father’s advice about looking the part. “That’s a good philosophy,” he says. “But that’s not really who I am so I stopped that. Now, whatever I’m wearing, I’m wearing.”

He listened to his wife, Stephanie, who had coached for a time in the WBNA. She had told him, when he was coaching their son in Pee Wee football, to tell the players clearly what he wanted them to do. “They don’t understand you,” she said to him. It was advice he could take to the NFL too.

There is no book.

In the second game of the next season, the Panthers — having already lost their first game — were up on Buffalo by three points with less than two minutes left. They were in field goal range and faced a fourth-and-1. The options were stark. They could go for it; if they got the first down, the game would be over. Of course, if they missed the Bills would need only a field goal to tie the game.

Then, they could kick the field goal. That’s what the book says to do. Kick the field goal, go up six, and the Bills would be forced to go 80 yards in less than two minutes and score a touchdown. Rivera barely hesitated. He had his team kick the field goal.

The Bills got the ball back, drove down the field and scored the game-winning touchdown.

Rivera could not get the decision out of his head. Nobody else in town could either. The Charlotte Observer called him out, saying it was fourth-and-1 for his future. The talk radio shows hammered him.

Two days later, he was driving home from the stadium late at night, and his mind was still on that play. The voice of John Madden was echoing: “There is no book.” Rivera mindlessly ran through a red light. Suddenly he saw the car about to T-bone him, and the next few seconds were squeals and panic and burnt rubber and heart-pumping adrenaline. The two cars had somehow managed to miss. And two lessons were clear. One: Pay attention when you’re driving. Yeah, that’s the obvious one.

But two, the big one, life is too precious to hold back and play scared.

The next week, the Panthers went for it on fourth down in a key moment. And the next week, they did again. And against Minnesota, they went for it twice. And they were winning. Suddenly, everyone was calling Rivera “Riverboat Ron.” Suddenly, the Panthers were playing the loose and free style he’d long wanted from them.

They won 12 of their next 14 games. And the players, for the first time, seemed to get what he was about — funny, driven, passionate, sober and a perfectionist.

The Panthers got off to a crummy start again in 2014, but they won their last four games to squeak into the playoffs.

And then this year…

“It has been magical,” Rivera says. “At first, when people talked about the best teams, we were part of the conversation. There were so many teams that were undefeated, and the attention seemed to shift from one to another. New England. Denver. Arizona. Cincinnati. Us.

“Then all of a sudden, we were one of three undefeated teams remaining. Then we were one of two. Then we were alone. And we’ve played so well together. Everybody lifts each other. The offense lifts the defense, the defense lifts the offense, special teams have been huge.”

When you ask him if this is the sort of year he imagined all those years he was preparing to be a coach, he shakes his head no.

“It’s never how you imagine,” Rivera says. “Things happen that you don’t expect. Everybody has a problem that you have to solve. … I have this little sign that I keep. It says, ‘Don’t draw me a map unless you’ve been there.’ Not a lot of people have been here.”

* * *

Ron Rivera will tell you that the best night of sleep he’s had all season — one of the best nights of sleep he’s had in years — was the Sunday night after Carolina’s loss to Atlanta. The Panthers were 14-0 going into that game. There was talk about them becoming the third team in the Super Bowl era to finish the regular season undefeated. Rivera wanted that a lot.

“To date, the only ones who really know what that’s like are Don Shula (with the 1972 Dolphins) and Bill Belichick (with the 2007 Patriots),” Rivera says. “I would have loved to have been included in that club and just see them and say, ‘Wow, that was something else.’”

The Panthers played their worst game of the season — “Not taking anything away from Atlanta, but we were not ourselves,” Rivera says — and they lost 20-13 despite having several chances at the end of the game. Still, Rivera slept soundly after the game.

MORE: Panthers’ secondary is vulnerable | Is Newton or Wilson tougher to stop?

Why? Rivera isn’t interested in that question. He used to worry about stuff like that, worry that people would pass judgment on him (“Does Rivera care enough?”) or take the wrong message (“Was he happy to be done with the burden of perfection?”). People have underestimated him for a long time. People underestimate his Panthers now — Carolina, even with the league’s best record, is only Las Vegas’ No. 3 choice to win the Super Bowl. So what? None of that matters.

“I’ve told our guys there’s only one thing we need to do,” he says. “We need to be ourselves. We need to keep our energy, keep our focus, play our kind of football. If we do that, there are no regrets.”

And with that, he goes behind his desk and pulls out a beautiful green book: “Vince Lombardi on Football.” Many coaches call it the bible. Rivera’s brother, Mickey, gave it to Ron as a gift. Mickey died after a two-year fight with pancreatic cancer. Ron thinks of him often.

“Does the football philosophy of Lombardi still hold up?” I ask Rivera.

“Yes,” Rivera says, but then he is quiet for a moment, and it is clear that he’s thinking of something else.

“When I see this book, I think of Mickey,” he says. “He got it. He understood me, and that was really the best thing. He wanted me to have this because he loved that I followed my dream and became a football coach. He believed in me.”

He looks at the “Lombardi on Football” book a little longer, and as he remembers his brother and the dream, it seems possible that what John Madden said wasn’t entirely right. Maybe there is a book. Maybe the thing that matters is how you read it.