Running is the past. Passing is the future. With completion percentages across the NFL continuing to rise, your average handoff seemed destined for the dustbin of inefficient history, nestled in between the midrange jumper and the sacrifice bunt. Yet, while their contracts have suffered, running backs are still here. So, welcome to … Running Back Day! We’re spending all day trying to answer the question of “What does it mean to be a running back in 2018?”

In the pantheon of the all-time most glorious NFL plays, there is no running back blitz pickup that could crack the top 500. You’re never going to see a rusher making a perfect, fundamental pass block on the cover of Madden, and those plays virtually never make the postgame highlights. The most famous and memorable running back pass block might be this non-block by former Colts back Donald Brown, who drew Peyton Manning’s ire when he ran the wrong way in protection.

But while the league’s most high-profile backs are best known for what they do in the open field, bowling over defenders, hurdling a corner on the edge, or taking a pass and diving into the end zone—the ability to scan the line, meet an oncoming linebacker head-to-head, and keep the quarterback clean in the pocket is still an important and underrated skill. And it’s harder—and way more complex—than you might think.

“Everybody says, ‘We want to create balance,’ but it doesn’t always end up that way,” Jerald Ingram, who coached NFL running backs for 19 seasons with the Giants and Jaguars, told me. “In this day in age, especially in the last 10 years or so, it’s important to make sure you’re protecting your quarterback.”

The Ringer’s 2018 NFL Preview Check out all of The Ringer’s coverage leading up to kickoff

Rush attempts in the NFL have steadily declined for the most part in the past decade following this century’s high-water year, and the NFL passing game—and quarterback contracts—have both exploded. As the league has trended toward a more spread-out, pass-happy game, running backs have become integrated pieces of downfield air attacks, regularly lining up all over the formation to run routes. But pass rushers have also gotten bigger, faster, and stronger over the last decade-plus, widening the athletic gap between defensive trench players and offensive linemen. Backs don’t pass protect on every play, but there’s still plenty of crucial times when they have to stay in the pocket to support overmatched tackles, guards, and centers, and more importantly, protect those well-paid and ever-important signal-callers. That can be a big ask for players coming out of the college game, who often face a steep learning curve.

“Some colleges do a great job of pro-style thinking, that pass protection is important,” said Ingram, “and some do not. So you have to educate that player. ... It’s the first thing you address, no matter if he’s a first-rounder, or a seventh-rounder.”

“And the [first] part is knowing who to block, not just how to block.”

For running backs, it’s not as simple as just picking up any free-blitzing defender coming for the quarterback’s head. The game moves too fast for that; running backs must be on the same page as the quarterback and offensive linemen before the snap, and his job changes from play-to-play based on what the defense is doing. “Depending on what team you’re on,” says Ingram, “you may have between 10 to 20 different protections per game.”

In a super-generalized version of pass protection, the quarterback or center makes a call prior to the snap, assigning each of the five offensive linemen a defensive player to block. Then, any other defender that rushes the passer becomes the responsibility of the running back—especially if a tight end is out running a route.

Except it’s almost never that simple: Defensive coaches will try everything they can to confuse protection schemes and force those quarterbacks to make the wrong call, getting offensive linemen to block the wrong guy—or no one—thus allowing a free rusher.

“[We played one] defensive coordinator,” said Ingram. “He would make all his defensive players 50-numbers. And that was to confuse the offensive linemen and the backs and receivers as to who’s the four-down linemen and who’s the Mike [middle linebacker]. And they’d all stand around and walk around and try to get a mistake—and a free blitzer.”

This is what’s known as an “amoeba” front—for its constantly shifting, amorphous nature—or a “psycho package.” When the quarterback or center comes to the line and sees seven or eight defensive frontline players, each a potential pass rusher, all milling about without declaring a spot on the line, the task of making sure everyone gets blocked becomes a little more tricky.

“You have to find the right [back] that can handle that kind of complexity,” said Ingram. “It changes: Who are the four down [linemen]? And who’s the Mike? Or who are the four down and the Will [weakside linebacker]? Then it goes to not just the assignment [the defender that the back is responsible for], then it’s a question of: Is the guy coming or not?”

Simply put, running backs have to be able to read a defense—and react in real time—in a similar manner to the quarterback.

Ingram laid out a few scenarios: “Is the free safety showing a tip that the weakside linebacker is coming down [on a blitz], because the safety has to replace that area? Is it a fire zone? Is it a shell look? Are they still going to bring the guy? Or is the shell look a decoy used to make sure the RB can’t chip to help the offensive line?” Whatever happens, the running back has to be aware, because his assignment can change with any movement before the snap.

Raiders running back Marshawn Lynch is one of my favorite players to watch, not just because he goes Beast Mode carrying the ball, but because he’s a force to reckon with as a pass blocker, too. Jon Gruden has plenty of things to worry about in getting his new-look squad off the ground, but Lynch’s ability to protect Derek Carr, the team’s $125 million man, isn’t one of them. Here’s Lynch, left on an island on the backside, picking up then-Eagles defensive end Vinny Curry, who at 6-foot-3, 279 pounds, outweighs Lynch by at least 50 pounds.

This clip below is even more impressive. You can see Lynch actually counting out the protections so he knows whom to block; Then, when the linebacker comes through untouched by the line, Lynch is there to engage him, maintain a clean pocket, and slam him to the ground.

As Ingram said, “A good running back will get into the heels of an offensive lineman,” meaning he rushes forward to meet the defender at the line. “He doesn’t just sit there, because if he waits, he’s in the quarterback’s lap, or he makes the quarterback flinch. A lot of defensive coordinators don’t care if [the pass rusher] makes the sack; if he makes the quarterback flinch, it’s more important than him getting the sack.”

For rookie running backs who are used to looking to the sideline prior to the snap for a big cue-card to tell him what to do, learning to read NFL defenses can be overwhelming. “One of the things I always do, one of the first meetings that we have ... is we learn about defense,” Packers running backs coach Ben Sirmans told media last June. “Learn how they will attack the offense; how they align; how they pressure; how they rotate; because, once they learn about the defense and then on offense, the [running backs] start seeing why we’re doing certain things.”

“Some guys would pick up on it just like that,” said Sirmans, “And other guys, they need a lot of trials and tribulations, especially based off what type of offense they ran in college. Because some guys, it’s a totally different world.”

This year’s rookie class is quickly finding that out. Buccaneers rookie back Ronald Jones is reportedly struggling with pass protection early on—and that’s something we saw in the team’s first preseason game.

In Miami, quarterback Ryan Tannehill recently threw Dolphins rookie running back Kalen Ballage out of the huddle for missing a protection assignment at practice. And in Seattle, the Seahawks, who have never hidden the fact that running back Rashaad Penny comes into the league with a lot to learn as a pass blocker, now face with the prospect of having to get Penny up to speed during regular-season action, when the games count. Penny broke a finger this week, an injury that will keep him out for three to four weeks and into valuable preseason and practice reps. If you believe Pete Carroll (and to be clear: I’m not saying you should believe Pete Carroll), issues in pass protection can “keep a guy off the field if he can’t do it.” And Penny’s still got work to do:

On that play from Seattle’s preseason Week 1 game, a touchdown throw from Russell Wilson to Nick Vannett, Penny did just enough to waylay Colts pass rusher Anthony Johnson—but per Seahawks offensive coordinator Brian Schottenheimer, Penny was supposed to cut block in that situation, and when he stayed up to block, the technique was lacking. Penny had his head down, and he hopped right before making contact, allowing the rusher to swim inside and affect Wilson. (Wilson strafed to his right and still threw the TD.) The effort, though, was definitely there. For some coaches, that’s a big deal.

“A lot of pass protection is want to,” said Ingram. “You get past that want to, he’ll do anything.”

But at some point, the correct techniques are crucial. “No matter what Lawrence Taylor does with his hips and his head, we don’t care; it’s what he does with his neck,” Ingram explains. “If you train your eyes to his neck and your foot to his crotch, you will do everything you can to put your body in between (the pass rusher and the quarterback).”

In other words, Ingram would teach his backs to aim their outside foot to the middle of the pass rusher’s body, which takes away the inside rush and forces the defender to go around toward the outside. “If you try to block Taylor toe-to-toe, with your toes even to his toes, he will dance around you, abuse you, or run over you,” said Ingram. “Maintain the integrity of the pocket. Give the defender one way to go. Not two ways.”

The third-down back used to be thought of as a change-of-pace receiving back. Now, with running backs like Todd Gurley catching passes on just about every down, the third-down back role has gotten a little bit more specific. As Rams GM Les Snead told The Ringer, “In today’s game ... third-down back means most reliable pass protector,” he said. “If you can’t pass protect, and everybody knows it, it does handicap the play-caller.”

That’s an important point, though it’s not the first priority. When it comes to the draft, as Ingram said, “You take the runner first. Then we can figure out how to get him to pass protect second. And, if he can’t pass protect, we’ll just scat protect.”

Scat protection is a five-man protection scheme that asks the running back to simply run a quick route to the outside to provide a dump-off option in the case of a blitz. Like this:

But being overly reliant on scat protection, as Snead suggested, does limit your options somewhat, especially on third down. This could mean fewer deep drops in the passing game, shorter routes, quicker throws, and much simpler schemes. It may mean teams need max protection up front (with an additional tight end or two), giving quarterbacks fewer options in the passing game. Let’s say it’s third-and-8, and you try to use a five-man scat protection against a blitz. That could make it tough for receivers to get downfield to the first-down marker before the quarterback has to get rid of the ball.

“You get into third down, and it’s a whole other world for people,” said Ingram. “That’s the difference between a college level and a pro player. Third down is the key.”

The three-down back looks poised to make a comeback in the modern NFL. Gurley just got paid, and guys like Le’Veon Bell, David Johnson, and Ezekiel Elliott are next in line. But a “three-down” back doesn’t just mean a player that can simply both run and catch passes. To play on third down, a running back needs to prove he can handle the complex world of pass protection, give his offensive coordinator the chance to utilize his full play-sheet, and perhaps most importantly, keep his quarterback on his feet.