Coach Bill Belichick is a four-time Super Bowl champion and one of the NFL’s most polarizing figures. (Maddie Meyer/Getty Images)

Last week, Bill Belichick trudged behind a podium wearing shorts and a sleeveless New England Patriots windbreaker, gray stubble dotting his face.

The assembled reporters had another round of questions about the status of Tom Brady, the quarterback embroiled in the most recent controversy that swarmed Belichick’s team. He deflected questions about Brady’s status and the functionality of his team’s offense without a determined quarterback. He discussed in detail the intricacies of choosing players for his practice squad. He refused introspection.

Belichick had risen from playing center at tiny Wesleyan University to the top of the NFL, along the way becoming celebrated for his brilliance and achievement but suspected of malfeasance and rule-skirting. He was asked what was the most important thing he had done over those four decades to evolve as a coach.

Belichick looked up from the questioner, gazed at the back of the room, and replied, “I don’t know.” He snorted. He stared. The room waited for him to say something else. He didn’t.

Belichick has left it to others to fill in the blanks behind his gloomy facade, and the effects of his success — admiration, animosity, loyalty, jealously — have created wildly divergent portraits. On Thursday night inside Gillette Stadium, the Patriots will open the season against the Pittsburgh Steelers, and Belichick will begin the defense of his fourth Super Bowl victory. He is 63 years old, the third-oldest coach in the NFL behind Tom Coughlin and Pete Carroll. Entering his fifth decade in the league, Belichick remains at the fore of NFL innovation. Defining him — and the roots of his success — remains elusive.

People close to him describe a reliable friend, a voracious learner, an ardent student of the game, a man whose grim public demeanor hides sharp intelligence and understated humor. He engenders loyalty with both surprising kindness and utmost competence. “As a player, what more do you want?” former Patriots safety Lawyer Milloy said. “You don’t want that fluffy [stuff]. He just wanted us to be focused on ball.”

Belichick’s detractors — and many within the league — suggest rule-breaking has propped up a brilliant football strategist. The SpyGate scandal remains a stain, a wound picked fresh this week by an extensive ESPN The Magazine story detailing the practice of filming and decoding opponents’ signals. In 2007, the NFL fined Belichick $500,000, but the scope and effectiveness of the scheme remain murky because of the league’s rapid investigation and destruction of video tapes.

Supporters, associates and former players say Belichick has adapted with a wickedly dexterous mind and a curious bent. “Probably the story of his career, from my vantage point, would be his attitude toward learning,” said Iowa Coach Kirk Ferentz, a Belichick confidante. Belichick once told his college economics professor that what he studied in class helped him stay under the salary cap. (“That’s an application of marginalism,” said Dick Miller, the professor.) His current defensive coordinator, Matt Patricia, was a rocket scientist before he became a football coach. Belichick seeks. He listens.

“It’s really amazing when you think about it: He’s been coaching longer than any player on this team has been alive,” Patriots special teams captain Matthew Slater said. “That says something about his leadership, the way he learns. The way he views the game is very unique. He’s been able to stay ahead of the curve because of the mind the good Lord has given him for football.”

“I hate to think what his IQ is,” Rick Forzano said of Bill Belichick. “He looks beyond what is happening.” (Charles Krupa/Associated Press)
‘Always moving forward’

For nearly three decades as a coach in the NFL, Belichick had divined creative solutions to complex problems, the skill that fueled his rise from playing center at Wesleyan to coaching at the top of the sport. On the day the Patriots arrived in New Orleans for his first Super Bowl as a head coach in late January 2002, he confronted a problem without precedent in his career: Milloy, his star safety, wanted a new hotel room.

At a walk-through practice, Milloy explained to Belichick that he had heard first-year defensive tackle Richard Seymour beaming about how spacious his room was. Milloy could barely squeeze luggage into his. What was up with a rookie scoring a bigger room than a veteran? “Really, Lawyer?” Belichick responded. Belichick was already trying to prepare a two-touchdown underdog to face the St. Louis Rams; he didn’t need another headache.

When Milloy returned to the team hotel after practice, a concierge greeted him with a key to a new room: “Big as hell,” Milloy recalled, and with a panoramic view of Bourbon Street, a Jacuzzi and, oddly, a treadmill in the corner.

At the Patriots’ team dinner that night, Belichick approached Milloy. “How do you like that room, Lawyer?” Belichick asked.

“It’s cool,” Milloy replied. “But I don’t know why they put that treadmill in there.”

“That’s because it was my room,” Belichick said.

Belichick grew up in Annapolis, drawn to football by the same innate pull that obsessed his father. Steve Belichick coached all over the country before he settled down as a Navy scout. He wrote a book, “Football Scouting Methods,” that became a bible among football intelligentsia. Bill followed his father on the road, where he watched Steve’s deathly serious attention to detail, and into coach’s meetings. Rick Forzano, a Navy assistant, would instruct 10-year-old Bill to break down film. Belichick would return with detailed notes, describing which receivers liked to run which routes on which downs.

“I hate to think what his IQ is,” Forzano said. “He looks beyond what’s happening.”

Forzano would later become the coach of the Detroit Lions, and he hired Belichick as a 23-year-old with one year of experience, a $25-per-week assistant job with the Baltimore Colts. Forzano still called him Billy. Belichick came to the Lions as a special teams coach, but soon his duties expanded to wide receivers and linebackers. His voice quickly became valued in meetings. One coach would suggest adjusting the position of the strong safety, and only Belichick would identify why it might affect the defensive end.

“Bill’s always moving forward,” said Al Groh, an assistant alongside Belichick with the New York Giants. “He’s not just thinking about this season. What is distinguishingly unique for somebody who is very bright and on top is he’s a terrific listener. He’s interested in anybody and everybody’s opinion because out of that might come a good idea. That was the case even when he knew he wanted to do.”

In Cleveland, his first stop as a head coach, Belichick would surprise assistants by raising ideas they had mentioned a month prior. He contacts college coaches and visits campuses. Friends have noticed him drifting away from one conversation to eavesdrop on another.

In the spring of 2007, Belichick — a better lacrosse player than football player at Wesleyan — called Johns Hopkins lacrosse Coach Dave Pietramala to congratulate him on winning the national championship. They talked on the phone for an hour. Later, after an awards banquet both men attended, they met at a restaurant afterward and chatted for three hours. Pietramala realized Belichick had as many questions for him as he did for Belichick. They still talk or text weekly.

“The amazing thing to me with Coach, he’s always in search of a way to do things better,” Pietramala said. “I’m really taken back at how inquisitive he is about lots of different things. It doesn’t have to be in coaching. If we have a guest speaker, he wants to know, what did he talk about? What was good about it? For a guy who’s extraordinarily bright, extraordinarily successful, he’s always searching for a better way, a different way.”

The depiction stands in stark contrast to the label many have affixed to Belichick: cheater. The Indianapolis Colts expressed suspicion that the Patriots bugged the visiting locker room at Gillette Stadium. At the Super Bowl earlier this year, Don Shula called him “Belicheat.” Even before SpyGate, one NFL coach was asked how he killed time at league meetings. He replied, only half-jokingly, “Sit around and talk about how much the Patriots cheat.”

‘He knew everything’

Former players insist Belichick did not have to cheat, that his knack for detail and recall gave him all the edge required. Heath Evans, a former Patriots fullback, ran off the field following a kick return, during which he had executed a block. Evans had kept his man out of the play, but Belichick informed him he had taken an imprecise angle, the kind of infraction most head coaches may not spot days later on film, let alone in the cacophony of a real-time NFL game.

“He knew everything,” Evans said. “Literally. He knew every detail. There was instant accountability, every second of the day. Bill just knew everything. It was scary sometimes.”

One season during his tenure in Cleveland, Browns coaches met with Chicago Bears coaches to swap notes about teams in their respective divisions. “I swear, he knew more about Tampa than the Bears, who played them twice,” said Ferentz, then Belichick’s offensive line coach. “Their guys were looking at us like, ‘Holy smokes.’ ”

Belichick prepares for everything. During staff meetings, he asks questions about a tactic an opposing coach used a decade prior. During Super Bowl XLVI, in 2012, the Patriots’ headsets malfunctioned in the second half, leading to harmful miscommunication. And so, in the week leading into last season’s Super Bowl, Belichick stopped practice and shouted for the coaches to drop their headsets.

In today’s NFL, most coaches rise and become head coaching candidates by mastering a specific area. Once they become a head coach, they hand off one side of the ball to a coordinator. Belichick touches everything in the organization, from scouting draft picks to an offensive lineman’s hand placement. During practice, he can spot a fullback missing a block out of the corner of his eye, halt the drill and correct the mistake himself.

“It’s still mind-boggling how I sat there and watch that take place,” said former Patriots linebacker Willie McGinest, now an NFL Network analyst. “He would break down both sides of the ball and be instrumental in planning every phase of the game. Other coaches can’t do that. That’s just amazing to me, having been in the league 15 years.”

Playing for Belichick can be stressful. Evans would pass him in a hallway or the locker room, and Belichick would present a situation and play and ask him, “What is their linebacker going to be thinking?”

The strict standard also brought comfort. Players understand their role with uncommon clarity, and they trust Belichick’s detailed instructions will reap success. “Playing for Belichick was the most pressure-packed and most peaceful experience of my career,” Evans said.

“He’ll put it up on the board,” McGinest said. “He’ll say, ‘This is what’s going to happen. This is how they’re going to attack you. If you do X, Y and Z, you’ll be okay.’ And it seems like every single week, it happens. So it’s not hard to play in that system.”

The Post's Adam Kilgore discusses how recent legal rulings could affect the way the NFL handles future cases. (Thomas Johnson/The Washington Post)
The Belichick guys

Mike Whalen was still groggy when he woke up the day after taking a new job in 2010. After four grueling days, he had resigned as the coach at Williams to take the same job at Wesleyan, a fierce New England rival but also his alma mater. While at Williams, Whalen had tried to introduce himself to Belichick as a fellow Wesleyan alum, but Belichick brushed him aside after a perfunctory greeting. But hours after accepting the Wesleyan post, he checked his packed voice mail, and one of the first messages came from a familiar voice: “Hey, Mike, this is Bill Belichick, head coach of the New England Patriots.”

Whalen called him back, and Belichick gave him a simple introduction: “Glad to have you back. Anything I can do to help, let me know.”

Belichick has kept his word. He has spoken at fundraisers at Whalen’s request, counsels Wesleyan players interested in coaching and responds each time Whalen e-mails him. Whalen once asked him how he would handle playing at Trinity, a rival with a lengthy home winning streak. In the middle of his own season, Belichick replied and told him to ask the players how many of them had anything to do with the streak.

“A few of the seniors had played there once,” Whalen said. “It was virtually irrelevant to three-quarters of our team. It gives you a little bit of insight into how his mind works.”

Belichick shows the public only his grim side, saying little and revealing less. Those who know him quickly point out his understated sense of humor, his thoughtfulness and kindness toward people who supported him. He sent Forzano a signed picture after the first three Super Bowls he won. “He’ll be sending me a fourth,” he said.

Ray Perkins, the head coach who hired him to coach linebackers for the Giants in 1979, asked Belichick in 2013 to attend a fundraiser at Jones County Junior College, where Perkins had become head coach. Belichick agreed instantly, traveling to Ellisville, Miss., and telling football stories on stage at a banquet. “He talked for 45 minutes,” Perkins said. “We had to drag him off the stage to get him to his plane.”

Pietramala has seen Belichick play video games with his 11-year-old twin boys, then drop to the floor and wrestle with them. Last season, after one of Pietramala’s players died suddenly, the coach asked Belichick for advice on how to handle his team. Belichick spent an hour on the phone with him.

“Not too many know him outside of the Gillette walls,” Milloy said. “Because that’s where he’s always at. The thing about the perception is, I’ll put it like this: Once you buy into the system, once you’re a Belichick guy, you’re a Belichick guy for life.”

But his team always takes priority. The list of Belichick guys Belichick has cut ties with for the sake of the salary cap is long. McGinest, Seymour, Logan Mankins, Deion Branch, Mike Vrabel, on and on. It even includes the safety to whom he once gave his hotel room.

Days before Week 1 of the 2003 season, Belichick told Milloy the Patriots would release him if he didn’t take a pay cut. Milloy refused. The Patriots waived him, and Milloy still chokes up discussing it.

Even as Milloy faced Belichick twice a season playing for the division-rival Buffalo Bills, they did not speak for three years. Milloy moved on to the Atlanta Falcons, who played the Patriots in the preseason’s first game in 2006. After the game, Milloy mingled with former teammates on the field. He felt a hand on his shoulder pads. When he turned around, he was shocked.

“Hey, Lawyer,” Belichick said. “Sorry for how everything went down.”

Like that, his animosity dissipated. The gesture was small and unconventional, perhaps open to interpretation. But to Milloy, it had meant everything.

“It was perfect,” Milloy said. “It was the Belichick way.”