Maybe greatness would still have happened if Dick Rehbein had lived. Bill Belichick’s first quarterback coach in New England loved the young Tom Brady, picking him from a group of passers the Patriots were considering before the 2000 NFL draft then begging his bosses to pick the kid who had been good but not great at Michigan. Who knows what they could have accomplished together.

“He was huge on Tom Brady,” Rehbein’s wife, Pam, told me in 2012.

But in August 2001, Rehbein’s heart stopped while undergoing tests at the hospital. His death came just weeks before the season and it left the Patriots without anyone to coach their three quarterbacks. Though his background was as a defensive mastermind, Belichick chose not to hire another quarterback coach, assuming the role himself.

Will Lady Gaga's Super Bowl half-time show get political? 'I believe in inclusion' Read more

What happened next might be the most serendipitous occurrence in NFL history. The 24-year-old Brady, who still hadn’t played a professional game, was given an opportunity few quarterbacks get: a chance to see his opponent’s defenses through the eyes of a defensive genius.

Forget all the talk about cheating or extreme workouts or the Patriot Way. Before the Super Bowls, Gisele and those nutty Trump endorsements there were Belichick and Brady locked for hours in a dark film room. And the biggest reason the two have won four championships together and may be remembered as the sport’s greatest coach and quarterback tandem might just be those video sessions that have taught Brady to look at the game a different way.

“I asked Tom once, ‘Is that film study why you are so confident out there?’” Damon Huard, Brady’s backup in 2001 and 2002, told the Guardian. “He said: ‘Yeah, it’s awesome.’”

Imagine being a given a remarkable gift when you are still young and talented and your mind is open to receive it. When Belichick first ran those quarterback meetings in 2001, he couldn’t have known he was turning Brady into an unstoppable force. It was an attempt for order at a terrible time. But the moment he flicked on the video machine, he switched his quarterbacks’ vision from looking at opposing defenses with an offensive player’s point of view to that of the defensive players themselves.

What Belichick taught Brady and the others in the room was to crawl in the heads of the men who would face them across the field. He showed them how to spot habits and tendencies and even insecurities. He made them see those men as those men saw themselves.

“He comes in and breaks down coverages for us,” Brady told the (Attleboro, Massachusetts) Sun Chronicle late in the 2001 season. “He probably knows what they are doing better than their players know what they are doing. You know he watches so much tape and he really has an understanding of their tendencies and the keys we should be looking at from a quarterback’s standpoint.

“I’ve learned more this year than I could ever have thought I’d learn in one season just in terms of knowing defense and knowing their philosophies. I mean he knows coaches too, so he knows their philosophies as defensive coordinators.”

Those who have played for Belichick say he has at least a mental file on every player in the league. Experienced players traded over, or signed as free agents, tell of being grilled for information on old teammates and coaches. The coach, they say, adores talking football, absorbing everything they say. Part of his brilliance, they add, is how he processes that information and then gives it to the team in a way they can use.

Huard, who went into the 2001 season as the Pats’ third-choice quarterback, behind then-starter Drew Bledsoe and Brady, was fascinated by Belichick’s film sessions. They were like nothing he had seen before as a quarterback, even if they ran for more than two hours without a break.

Belichick “would make a [video] package of, say, 15 plays of Champ Bailey.” Huard says. “There would be 15 clips of what Champ Bailey does when the ball is thrown to him. Or we would look at all the balls thrown at Charles Woodson and see how he breaks in cover 2 or man-to-man defense.”

The reactions of Bailey and Woodson, explained by a defensive savant like Belichick, gave the quarterbacks a unique grasp of how those players would react in all the situations they were likely to see in that week’s game. But he wouldn’t stop at the stars. He showed clips of all the other team’s defensive players, breaking down each by their responses in that team’s scheme. Essentially, the Patriots’ quarterbacks were watching what amounted to a video the other team’s defensive players would watch with their own coaches. It was not what other quarterbacks in the league were watching.

For Brady, the film study made a difference. Two weeks into the 2001 season, not long after Belichick took over the quarterback meetings, Bledsoe ruptured a blood vessel in his chest, nearly dying during the ride to the hospital. In Bledsoe’s absence, Brady – who had devoured Belichick’s video sessions, Huard said – built a connection with his coach. When Brady led the Patriots to a division championship and eventually the Super Bowl title, the job was solidly his and Bledsoe was traded away.

By most accounts, Brady and Belichick still study defenses together. Shawn Springs, who played against and with Brady during his 13-year career, spoke of it happening seven seasons ago when he was last in Foxborough. Springs said the film sessions were the base of what makes Brady so hard to defend.

“Tom Brady has the luxury of picking Bill’s great defensive mind,” Springs told the Guardian.

In fact, Springs said, there were many times in his year with the Patriots when Brady didn’t practice or barely even came onto the field for a practice. Instead, Springs said, Brady knew so much about the coming opponent’s tendencies there was no need to go through the pantomime of the Patriots plays. Brady might take some snaps to stay sharp and then turn over practice to his backup.

“Tom can just wait in the building holding a cigar and a glass of whiskey and be ready for that week’s game,” Springs said.

Facebook Twitter Pinterest Brady takes questions during media day. Photograph: Sean Ryan/IPS/Rex/Shutterstock

For several weeks at season’s end, the now-39-year-old Brady was listed on the Patriots injury report, leading to speculation as to whether he would play that week. Then not only did he play but did so brilliantly, setting an NFL record for best touchdown-to-interception ratio in a season. Was Brady even really hurt? Or was Belichick using the excuse of a sore knee to get his quarterback extra rest in a year where he already missed four games for his Deflategate suspension, keeping Brady healthy for the playoffs?

Maybe it was both, but there is no doubt Brady remains as dominant at an age when many stars have long since retired. This, Springs, Huard and others have suggested, is because he already has such a detailed knowledge of the other team’s defenses, he can move the Patriots downfield with minimal effort.

“You don’t want to rush him too much since he can just stand there and pick defenses apart,” Springs said.

“The only team that is going to beat the Patriots is one that can rush the passer with four players,” Huard said. “If you bring five or six guys, [Brady] is going to see it and find the man-to-man matchups. He’s going to have seen what those guys in the secondary do [from the Belichick tapes] and exploit it.”

Julio Jones: the Falcons superstar who can decide Super Bowl LI | Allen Barra Read more

Over the phone from Seattle, where he works as a fundraiser at the University of Washington (and is in the wine business with Dan Marino), Huard laughed.

“There must be a great element of confidence for Tom going into every game knowing he is over-prepared,” Huard said.

A few weeks ago Huard went back to Foxborough for the 15-year anniversary celebration of that first Super Bowl title. He marveled at how the others who gathered on the field were like him, long retired, yet there was Brady tearing through another team on the way to another division title. For a moment, he almost found the idea ridiculous. Who is this good for this long?

“I think of all the things I’ve done the last 15 years and here’s Bill and Tom still winning Super Bowls,” he said.

All the way back to those first awful days in 2001 when Belichick walked in the quarterback’s meeting room, flicked on the video player and built a dynasty.