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.

Shohei Ohtani rocked the sports world earlier this year when he came to MLB to both pitch and hit for the Los Angeles Angels. The 24-year-old phenom was a two-way revelation in Japan, but skeptics questioned the viability of any player, no matter how talented, splitting his time between two roles in the major leagues. Then Ohtani arrived in Southern California with his diving splitter and easy power and appeared poised to become baseball’s first dual-threat superstar since Babe Ruth. Before Ohtani injured his elbow in June, he posted a 3.10 ERA with 61 strikeouts across nine starts; at the plate, he’s batting .270 with 13 home runs.

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The NFL has long flirted with the idea of using some of its most talented players on offense and defense. When asked about the type of talent that might be capable of splitting time, Browns general manager John Dorsey summons a single name: “It’d be Deion.” Deion Sanders remains the go-to example of a two-way football star, but look back at his career and you’ll see that most memories of Prime Time scampering into the end zone didn’t come on offense. Across 14 NFL seasons, Sanders was targeted more than 30 times just once—with the 1996 Cowboys. In his career, he caught just 60 passes and had nine carries. Of his 22 career touchdowns, three came via receptions. Sanders is one of the greatest athletes to ever grace an NFL field, and even he was limited to mostly defense and special teams.

Every so often, another dynamic prospect comes along who dabbled in offense and defense in college and seems poised to continue that role in the NFL. Dorsey mentions Charles Woodson, whose multifaceted contributions at Michigan helped him win the Heisman Trophy in 1997. Three years ago, both schools in the USC-UCLA rivalry featured a two-way standout who developed into a first-round talent, yet Adoree’ Jackson and Myles Jack have played almost exclusively defense since arriving in the league. Jack was an All-Pac-12 linebacker who ran for 10 touchdowns over his freshman and sophomore seasons with the Bruins. When asked if he could see time in the backfield with the Jaguars, he was less than optimistic. “I think it would be once-in-a-blue-moon opportunity,” Jack says. “In my situation, we have Leonard Fournette.”

An Ohtani-like NFL figure would immediately become one of the biggest stars in sports, but the chances of one emerging are low. The presence of talented players throughout each team’s roster is a deterrent. Beyond that, the league’s infrastructure is built to dissuade players from splitting their time evenly between offense and defense. In the minds of evaluators and the players who’ve considered trying to go both ways, the risk of failing at one of those jobs is too great. “Maybe Superman’s gonna come one of these days,” Titans GM Jon Robinson says, “but I just think there’s so much that they have to know.”

The challenge for NFL evaluators in scouting college players is filtering NCAA action through a professional lens. When a scout watches a 55-52 Pac-12 game, for example, their task is to pare down what they see and discern how certain skills would apply to their team’s structure.

Minnesota GM Rick Spielman recalls watching Jerick McKinnon when the former Vikings running back was an option QB at Georgia Southern. When the then-FCS-level Eagles upset Florida 26-20 on the road during the 2013 season, McKinnon carried the ball nine times for 125 yards and scored the game-winning touchdown. “I’ll never forget watching the Florida game and seeing what he could do with the ball in his hands,” Spielman says. “He can score touchdowns for you. It all comes down to tailoring what you’re going to ask that player to do.” At McKinnon’s predraft workout in 2014, teams tried him out at several different positions, including cornerback and slot receiver. When the Vikings nabbed him with the 96th overall pick, though, they did so with the intent of making him a full-time running back.

“Maybe Superman’s gonna come one of these days, but I just think there’s so much that they have to know.” —Titans GM Jon Robinson on two-way players

McKinnon may not have played offense and defense, but his experience is indicative of how the process often works with two-way players in the draft. Robinson says that when he writes up notes on prospects, he keeps his projections contained to offense or defense, while mentioning whether a player can occasionally moonlight in another role. “I think you focus whatever side of the ball it is, but in your report you say, ‘Team X does use him offensively or defensively in this capacity,’” Robinson says. “‘It’s not out of the realm of possibility that we could use him there in a pinch.’” Even as Robinson parrots that caveat, his tone is skeptical. He says only a handful of players in a given draft class warrant that kind of note in the margins.

Part of the hesitation to use players two ways, especially if they’re young, is the amount of work it takes rookies to get up to speed at one position. That goes double for somebody like McKinnon, who had to transition into a new primary position. Every rep was crucial in refining his role. “From his rookie year to his second year, you could see the progression in him getting comfortable with that one position,” Spielman says, “even though he was a phenomenal athlete that probably could have played multiple positions.”

Further complicating matters is the lack of practice time players get from the start of rookie minicamp through the end of August under the current CBA. “Every minute you have with the players, you’re going to devote all that energy to be as good as he can be as his position,” Spielman says.

Evaluators seek to mine the best possible versions of their players, and that usually means drilling down on a single spot. “What gives you the best chance to win?” Robinson says. “Well, if it’s leaving him on defense, why are you going to take him off the defense to put him over on offense? You’re [diminishing] the return that you’re going to get on his play.” For some players, the idea of contributing both ways remains a dream—even if thus far it hasn’t matched up with reality.

During Jackson’s official draft visit to Tennessee in 2017, he sat in then–Titans coach Mike Mularkey’s office and heard a detailed pitch on all the ways that he could be used on offense. Jackson was mainly being scouted as a cornerback—by Tennessee and others—but had a wealth of experience as a receiver. He caught 39 passes throughout his three years at USC, including six for touchdowns, and many expected him to be a Swiss army knife from the moment he entered the league: He could work in the secondary, as receiver, and on kick and punt returns.

The Titans drafted Jackson 18th overall, and the initial excitement about his potential gave way to confusion when half the season passed without him getting a single offensive snap. “I wasn’t even trippin’,” Jackson says, “but two or three days before [I lined up on that side of the ball], someone in the facility asked me, ‘When are you gonna play some offense?’” Jackson got his first offensive reps when the Titans played the Ravens in Week 9. In the second half of the season, he carried five times for 55 yards. So far this offseason, even with former two-way threat Mike Vrabel replacing Mularkey as Tennessee’s head coach, Jackson has spent every bit of his practice time with the defense.

“Think of the hardest math you can think of. Egyptian scripture you can’t read. That’s how much of a difference it is. It’s not even night and day. It’s so much more.” —Myles Jack on the Jaguars’ defense compared with UCLA’s

During Jackson’s two-month stretch as a part-time offensive player last year, he says he never stepped foot into an offensive meeting. He’d duck into Mularkey’s offense to check out a play written on a card, or peek at a few designs before running them at practice. His free time for study was limited: 10 minutes before practice, the time before a workout or recovery, or the brief stretch when he was heading to or from lunch. “I’m focusing on defense,” Jackson says. “It’s not like I’m gonna come out here and run some routes. You either know how to run a route, or you don’t.”

Jackson says the workload was never too much for him to handle when he picked up shifts as a receiver at USC. He started his college career on offense, and his familiarity with the system allowed him to drift back and forth between units, hear one of the dozen or so play calls he’d memorized, and understand his task. In the NFL, memorizing even 10 or 12 offensive plays can be a burden, given the complexity of defensive schemes. At UCLA, Jack had no trouble learning a package of offensive calls during the Bruins’ final practice of the week. In Jacksonville, it’s a different story. “Think of the hardest math you can think of,” Jack says of the Jaguars defense. “Egyptian scripture you can’t read. That’s how much of a difference it is. It’s not even night and day. It’s so much more.”

Beyond the preparation, Jack and Jackson also identify in-game hang-ups. One major difference between the college and pro games is the distance between the hash marks. In college fields the span is 40 feet; in the NFL, it’s 18 feet and 6 inches. Because games at the NCAA level are so spread out, Jack accounted for his half of the field on a considerable portion of defensive snaps. The wider field lent itself to a condensed scope of responsibilities, limiting the toll on his body compared with the physical rigors of the NFL. “It’s a bigger, faster game, and to deal with that, you have to be at [your] top-end physical peak 100 percent of the time, every time you step on the field,” Dorsey says. “[By using a player on both sides], what you’re going to do is you’re going to short-change that athlete.”

The rest that comes with each change of possession is important, but another aspect of time on the sideline may be even more valuable. Jackson found last season that as he stood and waited for his turn on offense, he’d miss conversations about defensive adjustments, leaving him in the dark until he could confer with his teammates. “It could be something that you have an issue with, and if you’re focused on playing offense, you could be getting hit on that throughout the game and not even know it,” Jack says.

There’s something undeniably appealing about the thought of a two-way iron man breaking through in the modern NFL. It’s the reason Jack was such an object of fascination as a college player, and why Ohtani emerged as the spectacle in the sports world this spring. But as tantalizing as that type of player may sound, the barriers to ascension don’t seem set to fall any time soon. That hasn’t stopped Jackson from holding out hope one day, he—or someone else—will get a real chance to try. “I know for sure when [USC] went to Notre Dame, I played over 100 snaps that game,” Jackson says. “I think, mentally, it’s possible.”