In football, schematic innovation tends to trickle up. All of the new-age concepts you’ve seen infiltrate the NFL over the past few years were developed by coaches in high school and college. So, the premise of this list is a bit flawed.

The NFL has always been on a bit of an island. While lower-level coaches have never been afraid to experiment with new strategies, the pro coaches have been reluctant to adopt some of the things their peers are doing on Fridays and Saturdays.

It only takes one, though.

If one NFL coach has success with a certain concept, it’s not long before the entire league gets on board. Those guys may not have invented the strategy but they do deserve credit for bringing it to the NFL. All great coaches are receptive to new ideas.

Thanks to a handful of innovative coaches, the NFL game has changed dramatically over the past decade. Which coaches are most repsonsibile for those changes? Let’s figure that out…

1. Bill Belichick

This seems like an obvious answer but I don’t know how many football fans truly appreciate the influence a young Belichick had on modern defense. While in Cleveland, he and his defensive coordinator — some dude named Nick Saban — first developed the idea of pattern matching coverage. Everyone knows what man and zone coverage is, but Belichick and Saban created a hybrid of the two.

You’re probably wondering what a concept developed in the 1990s has to do with this decade. Well, Saban brought those coverages to the college level, and a few national championships later, almost every college defense in the country was playing some form of pattern match coverage. This was like 15 years ago. But that wasn’t really the case in the pros. Of course, there were teams that started utilizing those coverages at the turn of the century, but, even when Belichick was building his dynasty in New England, traditional, spot-dropping zone coverages were still the top option for most defensive coordinators.

That has started to change over the last decade, though. As passing games have grown more varied and complex, defensive coaches have had to adjust in order to keep up. Thanks to Belichick (and Saban), they have options outside of zone or man coverage.

(Obviously, Belichick’s influence extends beyond this one concept. I could have gone in a bunch of different directions with this one.)

2. Pete Carroll

Single-high coverages were popular well before Pete Carroll got to Seattle, but there’s no denying that the success he found with the Legion of Boom transformed the defensive landscape of the NFL for nearly the entire decade.

In retrospect, Carroll’s influence may not have been a good one for the rest of the league. Teams tried to replicate his Cover-3 and Cover-1 heavy scheme and didn’t have nearly as much success, which I wrote about my in my offseason series on the evolution of NFL defense. It turns out that running that scheme doesn’t work as well without Earl Thomas patrolling the deep middle, Richard Sherman eliminating one side of the field and Bobby Wagner, K.J. Wright and Kam Chancellor lurking underneath. Personnel matters!

Even still, Carroll laid the blueprint for how defense would be played in a post-Tampa 2 world. The NFL remains a single-high coverage league.

3. Chip Kelly

Stop laughing.

Are you done?

OK, I get that Kelly was ultimately a failure as an NFL coach, but there’s no denying that he greatly impacted the league in the short time he was a part of it. I think his schematic influence is a bit overstated, but some of the concepts he popularized during his time in Philadelphia have become NFL staples.

Kelly’s use of tempo has probably had the most profound impact on NFL strategy during the last decade. And that goes back to his time at Oregon when Belichick was picking his brain and had the Patriots running a no-huddle attack before the rest of the league caught onto the value of going fast.

Kelly’s biggest impact may have come off the field. His use of sports science was seen as revolutionary at the turn of the decade. Now it’s commonplace. And his streamlined approach to practice gave teams a model to copy after the 2011 CBA cut down on practice time, something NFL coaches are constantly complaining about.

There weren’t a whole lot of wins, but Kelly’s four seasons as an NFL coach reshaped the league.

4. Andy Reid

Reid has been a brilliant offensive coach for a long time, but I don’t know if he would have made this list if I wrote it a few seasons ago. In the past few years, though, Reid has evolved what was once a classic West Coast offense into something new.

He’s made the long-time NFL staple his own by blending it with concepts we were used to seeing on Saturdays but had never been the foundation for a consistently successful pro offense. Along with college staples like option run plays and RPO’s, Reid borrowed Air Raid passing concepts to help make Patrick Mahomes’ transition to the NFL easier.

Having a quarterback like Mahomes obviously makes schematic innovation easier, but Reid was having no problem getting top production out of Alex Smith using similar concepts. And as coaches from Reid’s tree have moved on to head coaching gigs of their own, his influence has only grown. It won’t be long before most NFL offenses resemble the scheme he’s crafted in Kansas City.

5. Kyle Shanahan

I suppose the elder Shanahan also deserves a ton of credit for influencing the league, but Kyle has taken the concepts popularized by his old man and dressed them up with mind-boggling pre-snap motions that leave defenses dazed and confused.

Shanahan has a distinct offensive philosophy — outside zone running plays meshed perfectly with a deadly play-action pass game — but he’s done a masterful job of adapting it based on his personnel. The best example being the 2012 season when he remade his offense to suit Robert Griffin III;s strength, and, in doing so, established the zone read as a concept that could work in the pros.

In Atlanta, he turned Matt Ryan into an MVP with an offense built around two versatile running backs and Julio Jones. Now, in San Francisco, he has the 49ers offense humming with a tight end (George Kittle) and an H-back (Kyle Jusychyck) as the focal points. Shanahan always gets the best out of his personnel.

Last year, Sean McVay was being hailed as the NFL’s newest genius, but his style was birthed by Shanahan. And Shanahan has been doing this offensive genius thing for a while now.