Positional distinctions are disappearing. Rushing yards are losing meaning. And offensive and defensive schemes are shifting from game to game — if not drive to drive. The most popular sport in America is changing faster than it ever has before — yet the way we talk about the game has largely stayed the same. It’s time for the conversation to catch up to the shifting concepts redefining front offices and gameplay nationwide. So welcome to The Ringer’s You Don’t Know Football Week, where we’ll explore and attempt to better understand the evolutions already occurring on the gridiron — and the reboots we’d like to see make their way to the game next.

Save for the lucky few anointed as quarterbacks, every kid who picks up a football starts as a wide receiver. At their core, backyard games are a series of one-on-one clashes between pass catchers and defensive backs, and the first challenge any aspiring gridiron star faces is learning how to get open. No skill on a football field is more relatable. No goal is more familiar.

That shared experience is part of what makes route running at the highest level so misunderstood. On one level, the idea of beating the person across from you is among the simplest in football. But against NFL cornerbacks, creating space requires as much nuance and attention to detail as any undertaking in the sport. “It’s all about efficiency,” Packers wide receiver turned running back Ty Montgomery tells The Ringer. “I think you learn that through repetition. How many steps [are you] taking at the top? How [are you] getting off the line? How are you creating separation? What ways are you able to make the same route look different every time you run it?”

Route running is a skill that’s both oft-discussed and underappreciated, and it’s become increasingly coveted in an era when many prospects come from spread backgrounds and have less formal training in that respect than ever before. The question, then, is what distinguishes a novice route runner from an expert—and how improvement happens. I talked to some of the league’s best receiving coaches and route runners to find out what goes into a part of the game that’s far more complex than it sounds.

When practices begin each season, Bengals wide receivers coach James Urban starts at square one with his players. Whether he’s working with six-time Pro Bowler A.J. Green or rookie first-round draft pick John Ross, Urban teaches every one of his receivers how to line up in a proper stance, which involves positioning the outside foot forward in order to create an initial burst with the back leg. “We use those foundations so when something kicks up or something isn’t quite as clean as we want it to be or doesn’t look right or the timing’s not right, I can say, ‘Hey, fix your stance,’” Urban says. “And then they know what that means.”

“That’s what scares a DB the most—[a wideout] going by him. Something that’s going to strike up the band and get the fans going. That makes a DB tremble and poo-poo in his pants.”

—Rams wide receivers coach Eric Yarber

Part of the goal is to create consistency among the receiving corps. Part of it is correcting the mistakes of players who have used the wrong get-off for years. Cardinals receivers coach Darryl Drake claims that making quick adjustments is especially crucial when it comes to young players. “It has to become a habit more than anything else,” Drake says. “And it takes a while when you’ve been doing it [wrong] for four or five years.”

From there, the next step is reinforcing the fundamentals: pushing off—and not dropping back—the outside foot at the snap, learning which foot to plant with on inside and outside cuts, and keeping one’s shoulders over the knees in order to stay balanced and give off the illusion of running a vertical route for as long as possible. These are the types of things that go unnoticed to the casual fan watching on TV, but serve as the building blocks for every receiver. And even for stalwarts like Packers star Jordy Nelson, there is room for small tweaks that can make a huge difference on the field.

When Green Bay wide receivers coach Luke Getsy arrived on the staff as a quality-control assistant in 2014, he introduced a new method for getting in and out of the break at the top of routes. By first planting on the inside foot—as opposed to the outside foot—when getting to the break of a route, the Packers receivers eliminated one small step and created a subtle but vital advantage. “By allowing us to get to that drop in [three steps] and letting our plant foot hit before or at the same time as the DB, we’re going to be successful no matter how good the DB is,” Nelson says. With 98 catches for 1,519 yards with 13 touchdowns, the 2014 season also happened to be the most productive of Nelson’s career.

For younger players, picking up on these types of tricks during film sessions and drills can mean transforming from an average route runner into a devastating one. During the early years of his career, Ravens running back Danny Woodhead had the privilege of playing alongside some of the best route runners at their respective positions that the game has ever seen: LaDainian Tomlinson, Antonio Gates, and Wes Welker. Each taught Woodhead something he’s carried with him for the rest of his career. “I’ve been fortunate because I’ve been able to play with some Hall of Famers,” Woodhead says. “It’s huge when you can watch someone who’s done it before, and not only done it before, but done it before at the highest, highest level.”

The mantra that Woodhead took from Welker was to try to make every route look identical until the last possible moment. These days, Woodhead will ask Baltimore’s linebackers if any slight lean or misstep gives away his routes during practice. For running backs, the goal when route running is to mimic the same release out of the backfield on every play. For receivers, the key is pushing vertically to make defenders think that they are streaking down the field each time they come off the ball. “That’s what scares a DB the most—[a wideout] going by him,” Rams wide receivers coach Eric Yarber says. “Something that’s going to strike up the band and get the fans going. That makes a DB tremble and poo-poo in his pants.”

Yarber says that the main weakness most young players have is a lack of patience. They lift their chests too early, tipping their hand and letting opposing cornerbacks know it’s time to slow down. Other young wideouts have a tendency to flail their arms to the side as they come to a halt—“the air brakes,” as Urban calls them.

Good route runners keep their bodies compact as they move up the field; the greats eliminate any possible indicator as to which direction they’re going. This obsession with deception has led some receivers to have coverage preferences that may seem counterintuitive at first brush. Cowboys slot receiver Cole Beasley says that while no receiver likes to be manhandled, he’ll take matching up with a tight press-coverage corner over trying to beat a defender who cedes a few yards of ground any day.

“I feel like from further off [from a defender], you have to be more precise with your movements,” Beasley says. “You could give something away easier because they’re looking at you from a further distance. They can see your whole body. But when you’re right there, there’s not much for their eyes to focus on.”

Learning how to master the mechanics is only part of the equation, though. To rise into the upper echelon, receivers must have not only a keen awareness of their technique; they also must develop a sense for what the defense is trying to accomplish.

“Running routes and attacking on air, not really having an idea what the coverage is, it’s really silly,” Packers tight end Martellus Bennett tells The Ringer. “You’re not really getting better because you’re not attacking different things.”

In Bennett’s eyes, becoming a great route runner has as much to do with knowing where to go as it does with how to get there. It’s a small distinction, but one that Chargers receiver Keenan Allen also feels is critical. “If you have a knowledge of the game and a knowledge of where you’re supposed to be in a sense, you can kind of get open without the technique,” Allen says.

Deciphering where to go against certain defenses begins with diagnosing the coverage. By identifying whether an opposing unit is Cover 2, quarters, or any other zone scheme, pass catchers are able to ascertain where the defenders over them will receive help. As soon as a wideout knows where a defense wants him to go, he can formulate a plan to get anywhere else. “If it’s Cover 5, where is the help?” Bennett says. “How are they trying to cover you? What does [the defender lined up over you] have to do? Where does he have to protect so that he doesn’t have help and you can attack that space to create yourself more space?”

Nelson’s favorite route against zone coverage is one he runs from the slot called a beeline. His aiming point is 4 yards underneath the near deep safety, a mark that changes depending on whether a defense has one or two players roaming in the back end. The beeline is a route the Packers have used for years that works well against a number of coverages; misread the defensive scheme, though, and it all goes awry. “Versus one-high [safety looks], it’s a great one,” Nelson says. “You sell vertical, [then] come across the middle of the field. The linebackers take their drops, and you hit it right between the two linebackers.”

It would seem as if man coverage might make things easier on a receiver, but all it does is incorporate another set of homework. As a tight end, Bennett can face up to five or six different defenders in a given game, and each requires a specific plan.

“When it comes to defenders, it’s about the guy you’re playing against,” Bennett says. “Are his hips tight? Does he want to turn and run? Is he a fast guy? Does he play off? It’s really just about knowing where he’s at and knowing what that defender is trying to do.”

For Allen, knowing an individual cornerback’s tactics and strengths can dramatically alter his approach. And while he likes going against press-coverage corners for the same reason as Beasley, he acknowledges that some defenders are so physical that separation becomes more important than deception. “[Broncos cornerback] Aqib Talib is overly aggressive, to the point where if he gets his hands on you, you’re pretty much dead,” Allen says. “I don’t want Talib to touch me.”

Any receiver can learn the ingredients that go into becoming an expert route runner, but it takes a certain kind of flair to mix all of those essential elements together to create a life-changing meal. Heading into each year’s NFL draft, fans and analysts alike fall in love with receivers’ heights and 40 times, occasionally forgetting that some of the league’s best pass catchers survive more on savvy than speed. Allen’s 4.71-second showing in the 40-yard dash at the 2013 combine (albeit with an injured knee) puts him in the fourth percentile of drafted players at the position since 1999, but few guys in the league are more adept at making corners look silly. “I’ve been shifty for a long time, just being able to make people miss,” Allen says, in one of the century’s most drastic undersells.

Allen is an inaugural member of the Always-Open Club and one of the best route runners alive, but the way he approaches his craft isn’t always how coaches like Drake, Urban, and Yarber would teach it. Urban and Drake emphasize that the best route is often the simplest one, involving as little horizontal movement as possible. “You [should never] let your feet get outside the framework of your body,” Drake says. “We don’t want any herky-jerky. You sell routes with your head and eyes.” This rule doesn’t always apply to Allen.

I see your bird's eye, and raise you a field-level. Amen pic.twitter.com/owGj6xhzBN — Sam Davis (@Sam_A_Davis) September 15, 2016

The above play—from Week 1 of last season, before the wideout tore his ACL later in the same game—is vintage Allen. He created instant separation against one of the league’s best corners to an extent that few receivers in the league could even dream of replicating. But some of his movements ran counter to the strategy that Drake espouses. Allen’s right leg moved far outside his frame, leading to more side-to-side movement than most position coaches would prefer. “My coach tells me the same thing—sometimes I’m doing it too wide,” Allen says. “At the same time, if I’m moving the DB and I’m quicker than him, it doesn’t matter.”

“When it comes to defenders, it’s about the guy you’re playing against. ... It’s really just about knowing where he’s at and knowing what that defender is trying to do.”

—Packers tight end Martellus Bennett

What allows Allen to get away with his absurd leg motion is his ability to stay balanced and explosive despite taking a horizontal step. The rest of his route is textbook. With three wide receivers lined up to the left (and out of the frame in the above GIF), Allen knows he’s matched up in man coverage against Kansas City’s Marcus Peters. The Chargers star’s initial burst looks identical to the outside release he would take if headed in that direction, yet by introducing extra lateral movement, Allen is able to riff on the standard set of rules with his own unique style. The result is almost unguardable.

“You’ve got a hesitation, and then off the hesitation, you’ve got the crossover,” Allen says as he watches a clip of the route. “It’s like basketball. Allen Iverson—he has a hesitation, and he has a crossover. He’s so fast on his way to the basket that when he uses the crossover, he can make it look like the hesitation.”

Allen isn’t alone when it comes to using signature flourishes to elevate what otherwise could be considered formulaic tasks. On this touchdown against the Packers in Week 6 last fall, Beasley put on a master class in deceiving a corner to sell a simple route. “All that’s in my mind is that I’m trying to make him think it’s a run play,” Beasley says. “I give him a little move at first to make him think it’s pass, but then I relax. You can fool guys with just body language. If you can get the DB to relax for just a slight second, right when he relaxes, that’s when I broke out. Then I know I’ve got him.”

That hints at another element of route running that flies under the radar: There’s a big difference between straight-line speed and the ability to shift between speeds, and players like Beasley thrive with the latter. Receivers who are adept at starting and stopping in an instant have the best chance of forcing defenders to turn their shoulders ever so slightly; as soon as that happens, the fight is won. “It’s the speed change from the pause to running the drag and making him say, ‘Oh god, now I’ve got to catch up,’” Beasley says. “Then I’ve got him right where I want him. When I’m running and I’ve got his shoulders turned, I can get out of [my break] quicker than he can.”

Like Allen’s wobbly-leg approach, Beasley’s impeccable sense for when and how to manipulate his movements to torment a defender isn’t something that can necessarily be taught. A lot of it comes down to feel, and even with all the mechanical aspects that go into the foundation of route running, that intuition—the same one athletes hone while playing in the park for the first time—still plays a major part in determining which receivers get open more than anyone else. Part of route running is a discipline; part of it is an art.

“There are always spots and always depths, but in the heat of the moment, that can change,” Woodhead says. “If you start thinking that, at least for myself, that’s when I become a robot. That’s when I cover myself.”