What’s valuable in the NFL? A great quarterback? Always—unless you’re the Eagles and can win with a backup. A great running back? Not usually—unless you’re the Rams and have Todd Gurley. A treasure chest of future second-round picks? Now you’re speaking Bill Belichick’s language. Welcome to Value Week, when we’ll be looking at what moves the needle for NFL teams—and what doesn’t.

During most of the last decade, the NFL’s highest-paid players have typically belonged to one of five so-called premium position groups: quarterback, edge rusher, outside receiver, left tackle, and shutdown cornerback. Conspicuously, those five spots directly relate to the two foundational tenets of the modern pro game: passing the football and defending the pass.

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As the NFL has become even more of a pass-happy league, though, a few previously subordinate position groups (or subgroups) have closed the gap on those “premium” spots. Top-tier right tackles, tasked with stopping a growing contingent of elite left-side pass rushers like Von Miller, are catching up with blind-side protectors in average annual earnings. Offensive guards aren’t far behind—a corollary of the explosion of top-tier interior pass rushers. Pass-rushing defensive tackles like Ndamukong Suh have, in a few cases, even leap-frogged some of the highest-paid edge rushers in average yearly salary. And, as NFL offenses increasingly utilize college-style three- and four-receiver personnel groups and spread formations, slot receivers like Jarvis Landry (who recently signed a five-year, $75 million extension with the Browns) can demand contracts that approach those of the guys who play primarily on the outside.

In fact, the slot receiver designation is becoming less important, as many of the league’s top pass catchers now regularly line up on the inside, too. Keenan Allen ran routes from the slot on 49 percent of his snaps last year, per Pro Football Focus; Larry Fitzgerald, on 62 percent of his snaps; and Adam Thielen, on about 49 percent. Tyreek Hill played in the slot on 35 percent of his snaps; Michael Thomas, 24 percent; and Julio Jones, 22 percent. But while the threat that pass catchers pose from an inside alignment has never been greater for NFL defenses, the slot cornerbacks assigned to match up with inside-aligned pass catchers have yet to see their contracts catch up to their brethren on the outside. That could be about to change.

There’s no officially recognized positional title—“middle-of-the-field second-level coverage defender” is probably a little too wordy—but with NFL passing games increasingly targeting defensive weaknesses in that area, defensive backs who play in the slot are poised to make up the NFL’s next premium position.

Up until the past few seasons, the term “nickelback” was most often used to describe a specialist or “sub-package” player—a backup third cornerback or safety who only came into the game on, say, third-and-long or other obvious passing situations—to match up with faster pass catchers downfield. Now, slot cornerbacks are no longer just a given team’s fifth-best defensive back—they’re a distinct and crucial position of their own. And the traits required to play that role are not the same as that of an outside corner.

“Your footwork, your hips, your change-of-direction speed: all that stuff needs to mesh to play inside because you have so much more area to cover,” said Matt Bowen, a former NFL safety who now writes for ESPN and coaches defensive backs at the high school level. “If you get beat on a crossing route in the NFL, you’re not going to catch up. You’re not. It’s not going to happen.”

Just ask new Texans slot corner Aaron Colvin, who got beat by Niners slot receiver Trent Taylor for a touchdown in last week’s preseason matchup. Often all it takes is one false step.

Whereas outside cornerbacks can utilize the sideline as leverage and squeeze opposing receivers into the boundary, slot corners and nickelbacks covering the middle of the field must rely on play recognition and elite quickness to stick with receivers. “Inside, they play two-way go,” said Bowen. “You have to play both an inside and outside release.”

Done right, it’s a thing of beauty. Here’s new Chiefs nickel corner Kendall Fuller breaking up a pass on Falcons rookie Calvin Ridley in preseason action last week; Fuller initially turns outside but when Ridley breaks to the inside on a slant, he’s flexible enough to flip his hips and explosive enough to close the gap and break up the pass.

In 2017, teams ran their offense out of three-plus-receiver sets on 63 percent of their snaps, per the Football Outsiders Almanac. That was up from 51 percent in 2010. Add in the invasion of hybrid-type tight ends and running backs capable of lining up anywhere in the formation as de-facto receivers, and defenses must account for more viable pass catchers downfield than ever before.

“We hear about ‘pro style,’” said Bowen. “Well, what is pro style anymore? Not the pro style I played against [before retiring after the 2006 season]. When I played, the backup tight end was the long-snapper. Now, the backup tight end is basically a big slot receiver.”

That shift on offense created a boom in the league-wide use of nickel and dime personnel. In 2017, teams ran with five-plus defensive backs on 65 percent of their snaps, up from 48 percent in 2010. On some teams, slot corners played even more than the top pass rushers. Veteran nickel corner Patrick Robinson, for instance, logged 710 snaps last year for the Super Bowl champion Eagles, outpacing key rushers like Brandon Graham (663), Fletcher Cox (607), Vinny Curry (576), and Chris Long (496). Nickelbacks log fewer snaps than corners on the outside, but like many of the league’s top pass rushers, a rotational role doesn’t negate their on-field impact. Because in the modern game, slot corners increasingly face the brunt of NFL passing schemes.

“Look at Philadelphia’s offense last year, with both Carson Wentz or with Nick Foles; Andy Reid’s offense; Sean McVay’s offense; or Kyle Shanahan’s offense,” said Bowen. “There’s quick passing, there’s play-action, there’s run-pass options, and inside vertical throws. … [Defenders] who play inside the numbers, that’s where the ball’s going more. Those are the guys that are going to be around the football more.”

The numbers seem to back that up. With a surplus of slot receivers and hybrid pass catchers at their disposal, quarterbacks are targeting the middle of the field more—and with elevated efficiency. All but six quarterbacks threw a greater number of passes to the slot than out wide in 2017, noted Football Outsiders’ Scott Kacsmar. And “for the second year in a row, [FO] observed that the shorter, higher-percentage throws associated with the slot produced better DVOA than throwing to receivers lined up out wide.”

“DVOA on passes to slot receivers improved from 2.1 percent in 2016 to 4.6 percent in 2017,” writes Kacsmar, while “DVOA on passes to wide targets declined from negative-1.0 percent to negative-2.9 percent.”

The efficiency of slot routes helps illustrate the growing importance of inside coverage defenders. According to Football Outsiders, middle-of-field-breaking routes like digs, slants, posts, and seam routes all produced positive DVOA last year, while outside-dominant or out-breaking routes like fades, comebacks, outs, and curls all produced negative DVOA. The go route was the only predominantly outside route to produce a positive DVOA.

The explanation for these splits is pretty simple: The timing and precision, arm strength, and accuracy required to complete many of those outside-the-numbers throws is greater than most of the inside throws quarterbacks typically make.

“If you’re a quarterbacks coach,” asked Bowen, “would you want your quarterback to be on the far hash and to throw an out route? Or would you want him to throw a crossing route or a seam route right in front of him? You throw an out route that’s not on time, and it might be on the back shoulder against Jalen Ramsey, that’s going back for six. You gotta be careful with that stuff.”

Inside routes didn’t become more efficient overnight, though. Widen the scope to the past decade, and the splits between slot and outside throws look similar. As Pro Football Focus’s Eric Eager and George Chahrouri note, going back to 2007, throws to slot receivers have produced a higher EPA, or expected points added, than throws to outside receivers. In other words, they wrote, “Throwing to inside receivers is not only a better play, it’s a safer play for offenses.”

Of the 20 highest-paid cornerbacks in the league by average annual value, all but one—the Titans’ Logan Ryan—are predominantly outside corners (though the Chargers’ Casey Hayward signed his deal after playing in the slot in Green Bay, he has played all but 74 snaps on the outside for the Chargers the past two years in place of the injured Jason Verrett). Add in this year’s free-agency numbers, and it might seem like the NFL is completely unaware of the success quarterbacks are having passing the ball to receivers lined up in the slot.

Teams handed out big-money deals to outside corners: Trumaine Johnson got a five-year, $72.5 million deal from the Jets that averages $14.5 million a year. The Titans signed Malcolm Butler to a five-year, $61.3 million deal that averages $12.2 million a season. Kyle Fuller’s four-year, $56 million deal with the Bears averages $14 million a year, while Prince Amukamara’s three-year, $27 million deal with the team averages $9 million per year. Richard Sherman, 30 years old and coming off an Achilles rupture, got a deal worth up to $9 million per year. Meanwhile, slot corners Aaron Colvin (four years, $34 million; $8.5 million per year), Nickell Robey-Coleman (three years, $15.6 million; $5.2 million per year), and Patrick Robinson (four-years, $20 million) each failed to garner the same kind of cash.

Part of the reason for the slot corner’s depressed value may be because there are very few superstars—or even truly complete players—playing the position. It’s just rare to find a player who checks all the requisite boxes. A nickel corner who can cover but is a liability as a tackler can be attacked by opposing offenses. “Inside the numbers, you’re going to have to make more open-field tackles,” said Bowen. “Not just contain a guy or force a guy to the edge … but to tackle in space, and [often], that’s against big-time running backs. There is an element of physicality there.”

And that’s not just against the run. “For [some] teams that play zone,” said Bowen, “if they throw the ball outside on a swing route to the running back, or they toss a bubble screen outside, that’s you; you’ve got to make the tackle in space.” If that slot corner is too easily blocked or unreliable as a tackler, offenses will target him. Conversely, a nickelback who can play the run but can’t be trusted to cover everyone on the opposing offense is essentially just playing a linebacker role. NFL teams, in other words, need playmakers who can do it all. Guys like Texans safety Tyrann Mathieu, who was, at one time, the league’s most complete slot cornerback, capable of covering on the inside, blitzing, and defending the run.

Still, we could be on the cusp of a changing tide in favor of nickelback defenders. For one, Butler’s deal in Tennessee could give Ryan the chance to move back into the slot more frequently, where he’s at his best—and on a three-year deal that averages $10 million per year, a move inside would make him the highest-priced slot corner in the league. Past that, the criminally underpaid and underrated Chris Harris, whose contract is up at the end of the 2019 season, will be due for an extension as early as next fall.

Even more evident, the first round of this year’s draft could signal a change in the prestige of that position, as Minkah Fitzpatrick (11th overall), Derwin James (17th), Jaire Alexander (18th), and Mike Hughes (30th) all bring the potential to factor as nickelback defenders early in their careers.

Fitzpatrick in particular, has a chance to emerge as the new poster boy for the slot corner position in the league, a role left vacant since Mathieu went down with his second ACL tear in Week 15 of the 2015 season. The former Alabama defensive back (he played the STAR role in Nick Saban’s scheme, a combination of inside corner, safety, and linebacker) is the prototype of a modern defender: One who can line up on the inside, cover, tackle, and run step-for-step with any opposing pass catcher, whether that’s a slot receiver, tight end, or running back out of the backfield. Oh, and he can hit:

“His role now, if I were the coach in Miami, would be to just unleash chaos,” said Bowen. “Let’s move him all over the place. You got a tight end? I’ll take him out of the game. You got a running back who they can remove from the formation and run routes, like Christian McCaffrey? Well guess what? I’ve got a matchup for you now with Minkah Fitzpatrick.”

Fitzpatrick’s versatility should allow him to stay on the field in any situation. “The other thing is he tackles,” said Bowen. “You can drop him down into the box [on anything] from third-and-2 to third-and-6, and we’re comfortable with him there. You wanna run a toss scheme, or a stretch scheme with your running back, he can defeat a block and make a tackle so you can get off the field.”

Fitzpatrick still has much to prove, and there’s no doubt he’s going to get beat from time to time matched up with All-Pro players in the NFL. But the Dolphins’ rookie Swiss army knife has the skill set that every defensive coordinator is going to be looking for from here on out. As the lines continue to blur between the running back, receiver, and tight end positions, defensive coordinators are going to need players who can match up with any and all of them.

“The interesting thing to me, go back about seven or eight years, and the term ‘hybrid’ was a negative,” said Bowen. “You didn’t really have a position; Where are you going to draft him? Where are you going to play him?

“Now, you gotta have those guys.”