Bill Belichick has managed to create a legacy without leaving a footprint. That is very difficult to do.

We’re not talking about the various “Gate” cases, a subject we’ll leave for another time as Belichick prepares to coach the Patriots in the Super Bowl for the sixth time.

All the great coaches before him generally have had some lasting influences.

Paul Brown called the plays for his quarterbacks decades before that became s.o.p. and also fully integrated his roster long before everyone else did it.

Vince Lombardi was so influential that the NFL’s championship trophy is named for him.

Sid Gillman virtually invented the modern passing game and influenced legions of coaches who came after him.

Bill Walsh created offensive and organizational systems that spread, at least in part, to every team in the league.

Belichick? All he does is win, trailed by controversy. He doesn’t even spawn a coaching tree as many of the greats do. Most of his assistants who struck out on their own — Charlie Weis, Romeo Crennel, Eric Mangini, Josh McDaniels — flamed out. His fingerprints are on every corner of everything the Patriots do, but his influence does not go beyond that.

As a result, and this may not be a popular position to take, but Belichick may indeed be the greatest coach of the NFL’s modern era. Sure, he bends the rules, occasionally even breaks them. (Although criticism of his “ineligible receiver” gambit miss the point because that is an entirely legal maneuver, more on that later.)

But — and is this not the perfect metaphor for the “me” generation — Belichick doesn’t care what you think of him or what you say about him. Coaches are always single-minded but he takes that attitude to a new level. Even his supposed mentor, Bill Parcells, left a trail behind by his ability to jump jobs and revitalize teams, but it’s worth pointing out that Parcells never won a playoff game without Belichick on his coaching staff.

No one, certainly not the late Cleveland Browns owner, Art Modell, ever saw this coming. Belichick was Modell’s coach for a time in the ‘90s and was so toxic a presence he was blamed in part for the team’s decision to move to Baltimore.

Later, Belichick quit on the New York Jets after less than 24 hours as their coach to become coach of the Patriots in a swirl of controversy that cost New England draft choices and, in retrospect, should be seen as a harbinger.

There is reasonable belief that Belichick wouldn’t even be the favorite house guest of his boss, New England owner Robert Kraft, who, even while enjoying all the Lombardi trophies Belichick brought to him, once called his coach a “schmuck.”

Belichick is a brilliant coach with the personality of a radish. He is remarkably well-read and may own the largest library of football coaching books on the planet. He was a defensive coordinator before becoming a head coach but since then has been heavily involved in both the offensive side of his team and the special teams.

When New England won Super Bowls early in Belichick’s reign as the coach, much credit also flowed to Scott Pioli, his personnel guru, for assembling the roster. But Pioli failed when he struck out on his own and Belichick has continued to win.

And while critics say he has had it easy with Tom Brady as his quarterback all those years, who made the decision to keep a young Brady as the starter when the predecessor, Drew Bledsoe, recovered from an injury — and after Bledsoe saved an AFC championship game?

Sure, 12 division titles in 14 years is an impressive number in an era when rosters must constantly be made over, but Belichick might have done his best work after Brady missed virtually the entire 2008 season due to injury and the Patriots finished 11-5 behind a backup quarterback, Matt Cassel.

At least a part of Belichick’s genius lies in his lack of an ego.

He is unafraid to steal from others and unafraid to give them credit, too.

The “ineligible receiver” formation he used in the playoffs came straight from Alabama coach Nick Saban, who was Belichick’s defensive coordinator at Cleveland.

But Saban is not the only college coach Belichick acknowledges stealing from, and not even the primary one. Belichick has forged a close relationship with Urban Meyer, the Ohio State coach who used to be at Florida, close enough that the two men have studied each other’s practices and addressed each other’s team in meetings. They have exchanged strategies and philosophies.

In a 2008 interview, Belichick told me, “For him to watch us practice, watch me for a day or a day and a half, and to be able to say something as an outsider (is valuable). Frankly, he’s had a chance to observe a lot more pro (teams) practice than I have. I only see this organization . . . He has a viewpoint on what we’re doing and, whatever his thoughts are, I think the team is very receptive to hearing them.”

Belichick added, “Sometimes, I bounce stuff off him. Sometimes, he bounces stuff off me. I value his opinion and advice when he gives it to me. I appreciate it.”

That openness — and acknowledgement of it — is rare. Bill Walsh, the late Hall of Fame coach who created the San Francisco 49ers’ dynasty in the ‘80s, used to complain that Steve Mariucci, who coached the 49ers for a half-dozen seasons beginning in 1997, never asked him for advice, even when Walsh was the team’s general manager.

“I could help him, you know,” Walsh frequently used to say.

But Belichick does not mind learning from others.

“Bill is always looking to find out new stuff and he doesn’t care (where it comes from),” Jim Fassel, the former New York Giants coach, once said. “That’s the unique thing about Bill, because you can’t in this profession let your ego get in the way . . . all you want to do is to do things that make you win.”

Ira Miller is an award-winning sportswriter who has covered the National Football League for more than three decades and is a member of the Pro Football Hall of Fame Selection Committee. He is a national columnist for The Sports Xchange.