Positionless defense has been a term thrown around NFL circles for years. Like most things in professional football, there has been a consistent evolution of the phrase and practice.

Lately, we’ve experienced the Moneybacker, originated by Deonne Bucannon and the Arizona Cardinals, which was basically just a safety moved to full-time linebacker. That trend shifted toward the rise of the box safety, like a Landon Collins, who plays a majority of his snaps closer to the line of scrimmage but will take on more traditional safety responsibilities.

More recently, the lines between positional responsibilities have blurred and that’s when players like Tyrann Mathieu and Jamal Adams can have stretches in 2019 when they served as their team’s best safety, linebacker, slot corner, and pass rusher. Mathieu took that role into hyperdrive in the playoffs and help the Kansas City Chiefs win the Super Bowl, while Adams parlayed his versatility into a trade away from the New York Jets and a likely massive new contract with the Seattle Seahawks.

Most importantly, these are players that aren’t coming off the field, regardless of the situation and they can bounce around the defense. A few years ago, a player like Mathieu, who might have been relegated to a small slot corner, would have been taken off the field against heavier personnel. But now his versatility is considered an asset. Hybrid is no longer a dirty word, it’s embraced. 

So much of the impact brought from these kinds of players comes from how they can control the middle of the field, which typically brings the highest value for opposing offenses. While offenses throw to the short outside most often, the highest success rate comes from the intermediate seams.

For the Chiefs, the addition of Mathieu helped push down both the targets and success rate against the defense from what it was in 2018…

…to what is was with him 2019:

Kansas City got improved play all across the secondary, but Mathieu’s ability to move around helped everyone else in that unit play better. Juan Thornhill was able to play deep. Daniel Sorensen could play more in the box. The corners could worry about the outside and the linebackers didn’t have as much coverage on their plate. All of those responsibilities were lessened because Mathieu could fill in the gaps as the other defenders played to their strengths. This was highlighted even more in the playoffs after Thornhill tore his ACL and Mathieu was a super defender for Kansas City.

Defensive players like Mathieu aren’t just more valuable because of the individual versatility each can bring to the field, but these types of special players fundamentally change how the defense can attack an opposing offense.

For the majority of the time, the defense is reactionary to what the offense presents. Sure there are some aggressive defensive calls that put that side of the ball on the attack, but more often than not, the defense has to play catch up to what the offense is dictating. That’s now especially true with matching personnel. The offense sends out the personnel it wants on the field and the defense calls its personnel to match.

The problem for defenses now is how versatile offenses have gotten from differing personnel sets. Offenses — at least the smarter ones in the league — have embraced the mismatch of running from light personnel and passing from heavy sets. It’s its own sort of pre-snap play-action by making the defense think one thing and do the other.

Last year, the most advantageous matchup for an offense to run the ball came from 11 personnel against dime defenses, per data from Sports Info Solutions. There were just below 600 such plays last season (598) which accounted for 10% of runs from 11 personnel. But on those plays, runs had an EPA per carry of 0.18 with a positive play rate of 51%. Runs from 11 against nickel (five defensive backs) averaged 0.00 EPA per carry with a 49% positive play rate. The average run across the NFL had -0.03 EPA per carry and 47% positive play rate in 2019. Offenses gained the biggest advantage running when the defense sold out for the pass. 

The opposite holds true for the pass. Some of the most efficient passing plays last season came from 12 personnel (two tight ends) when the defense played base with just four defensive backs (0.10 EPA per attempt. 51% positive play rate).

A wave of highly athletic tight ends has helped start this shift from the offense. Travis Kelce is listed as a tight end and treated like that by some opponents, but he’s really just one of the NFL’s best slot receivers, granted, a slot receiver who stands at 6-foot-5 and 260 pounds. With Kelce on the field, the Chiefs’ 12 personnel can easily act like 11 and 11 personnel can become 10. 

Having defenders who can stay on the field in those situations and play against all possibilities is now more important than ever. Offenses have become more versatile out of varying personnel deployments and the next era of defense must include defenders who can do the same on the other side of the ball.  Playing them in nickel can keep run responsibilities that would be found in base and dime can act like nickel, all while giving defenses more assets against the opposing passing game.

Jamal Adams and the Seahawks could be a test of this philosophy. Last year, without much secondary depth, Seattle ran the highest rate of base defense in the league at 67% (the next highest team was at 37%). The Seahawks used base against 11 personnel 53% of the time and were actually more successful with that defense (-0.12 EPA per play and a 48% success rate allowed) than when they matched 11 with nickel on 41% of plays (0.20 EPA per play and 51% success rate allowed).

Part of that is because the Seahawks have two elite coverage linebackers in Bobby Wagner and K.J. Wright (Wright had 11 passes defensed in 2019). But now with Adams in the fold, as well as slot cornerback Quinton Dunbar and midseason trade acquisition Quandre Diggs, Seattle has a stronger secondary that can match up against any type of personnel. In nickel, Adams could move down into the box and the Seahawks won’t lose anything off their run defense and they add more in coverage. Adams has also been a great blizter throughout his career and could add another element to a defense that rushed four on the ninth-highest rate (72%) last season and now won’t have Jadeveon Clowney

Even with those elite coverage linebackers and with a shift away from the old Cover 3 shell of the Legion of Boom era, there wasn’t a lot of disguise on the Seattle defense. A player like Adams changes that. His presence on the field and even his alignment doesn’t tip off what the defense is going to do and that gives less information to the opposing offense and provides a boost to the other defenders on the field.

There might not be a better example of how one player can shift a defensive philosophy than Derwin James of the Los Angeles Chargers. During James’s rookie season in 2018, the Chargers used dime with six defensive backs as their base defense on 64% of snaps. James’s ability to play all over the field and handle different responsibilities was a significant part of that. James could cover ground as a deep safety, stay in man coverage like a cornerback, stuff the run like a linebacker, and rush the passer like an edge rusher. 

In 2018, the Chargers matched up with 11 personnel in dime 61% of the time and with seven defensive backs another 16%. They even threw out dime against 12 personnel 35% of the time.

But when James was injured during the 2019 preseason, the Chargers had to fundamentally change their defensive strategy. The personnel and defensive responsibilities became more traditional. Without James on the field, the Chargers countered 11 personnel with nickel 77% of the time and dime just 17%. Against 12, the Chargers used base 47% of the time and nicked 50%.

As soon as James came back, he was put right back into his old role. He didn’t replace a defensive back in his return. Instead, he took a linebacker off the field. The Chargers went back to 51% nickel and 47% dime against 11 personnel and 23% base, 68% nickel, and 9% dime against 12. 

One of the goals on offense is to create and exploit mismatches against defenders — receivers against safeties, running backs against linebackers, tight ends against anyone smaller or slower, etc. But having a player like James, who can stick with any type of player in coverage flips that mismatch.


Derwin James is the peak of this type of versatility, but others can make the same type of impact in shifting how a defense plans its attack. Even for those playing more traditional positions, the ability to jump into other responsibilities and limit those mismatches, or even swing the pendulum the other way, is an invaluable skill.

Fred Warner plays inside linebacker for the San Francisco 49ers but has the range to do just about everything in the middle of the field. On the play below, the Baltimore Ravens had three receivers to one side of the field, but the two outside receivers were tight ends and the innermost receiver was rookie speedster Marquise Brown. That specific trips alignment would trip up almost any defense, but the Niners were able to keep their assignments and allow Warner to carry Brown down the seam. Marquise Brown one-on-one with a linebacker is something the Ravens will take every time, but Warner had the speed and instincts to stick with Brown and force a pass breakup.

With the increased usage of pre-snap motion from offenses, there are more last second shifts to defensive responsibilities. These mismatches are getting created with barely any reaction time for the defense. While communication is key, having the type of defender who can run with any type of player from any spot on the field helps keep that disadvantage at a minimum.

The NFL has seen a number of athletic and versatile defenders enter the league over the past few seasons. Many of these are guys who have moved around more often at the college level and NFL teams have started to embrace that type of versatility at the next level. While Warner plays as a somewhat traditional inside linebacker now, he was a slotbacker/safety hybrid at BYU who tested as an 80th percentile athlete as a linebacker at the Combine.

San Francisco’s division rival, the Arizona Cardinals, will hope the eighth overall pick in the 2020 NFL Draft Isaiah Simmons can be their version of Warner. Simmons bounced between linebacker and safety at Clemson and at 6-foot-3 and 238 pounds, tested as a 98th percentile athlete at the Combine.

Simmons drew some comps to Derwin James in the draft process and while that’s a bit of a stretch, Simmons projects as the type of do-it-all defender the modern NFL is looking for. The early word from the Cardinals is that defensive coordinator Vance Joseph was going to stick Simmons in a traditional linebacker role as he gets used to playing at the pro level.

But even if that’s the case and Simmons fills into more of a Warner or Wagner type role to start, his coverage skills and the ability to match up with players across the offensive spectrum will be an advantage for the Cardinals.

Arizona is also doubling down on the positional versatility by throwing Simmons next to Budda Baker, who just became the league’s highest-paid safety. Baker has played all over the defense for the Cardinals. PFF charted him with 544 snaps at free safety, 340 in the box, and 182 at slot corner in 2019.

Coverage has been an issue for Baker and no team was worse against short passes by DVOA in 2019 and the Cardinals ranked just 25th against deep passes by DVOA last year. But Baker has made up for that by making plays all over the field. He led all safeties in Defeats per Football Outsiders (Jamal Adams was second) with the most Defeats against the run and tied for third against the pass among safeties.

The idea with the two of them together, there won’t be many mismatches one of them can’t handle against opposing tight ends from any alignment and personnel grouping. That’s a place where the Cardinals were killed last season — 32nd in DVOA against tight ends.

Arizona is banking on Baker and Simmons becoming an important duo together on a young defense, especially against the rest of the NFC West. The 49ers are going to run and throw well from both 12 and 21 personnel. The Los Angeles Rams can go from spreading the field to run from 11 to sticking with an increased usage and pass rate from 12 to continue how they ended the 2019 season. The Seattle Seahawks might run the ball too much, but they can mix and match the secondary passing weapons to go along with Tyler Lockett and D.K. Metcalf on the outside.

Over two games in 2019, the 49ers used 21 personnel on 23 plays against the Cardinals. Arizona stuck to a base defense for 22 of them. For most teams, that screams run but the 49ers have legitimate passing weapons from that personnel grouping with George Kittle and Kyle Juszczyk. With that, San Francisco had a 77% pass rate on those plays and averaged 0.30 EPA with a 55% success rate. And while that’s only 22 plays over a full season, it was 17% of the plays between the Arizona defense and San Francisco offense in divisional games with one team having a distinct advantage on all of them.

Simmons was the first hybrid player taken in this past April’s draft, but he was not the last. Nearly every safety in this draft class had some experience all around the back end of the defense, at the least. That alone shows how far the positional evolution has come. But two teams used second-round picks on smaller school players who have the positionless skillset with plus athleticism.

With the 37th overall pick, the New England Patriots selected Kyle Dugger of Division II Lenoir-Rhyne. At the end of the second, the Carolina Panthers picked Jeremy Chinn of FCS school Southern Illinois. Both were among the biggest and most athletic safeties in the class. Dugger measured in at 6-foot-1 and 217 pounds while Chinn was 6-foot-3 and 221 pounds. Both were 99th percentile athletes at the position per SPARQ composite scores.

Both are likely to see action sooner rather than later in their rookie seasons. Dugger has moved up the depth chart by way of opt-outs in New England (he’s been one of the top playmakers in camp) and Chinn is already a big piece of a young revamped defense in Carolina. 

How these rookies fare early in their careers is unknown and there is no guarantee. In the past, these small school prospects with limited high-level playing experience would have been overlooked and not considered until the late rounds. Instead, these players were picked in the second round and may find their way into starting roles soon. Clearly they presented a skillset valued highly by some NFL decisionmakers. That might be a hint toward what defensive coaches around the league are looking for to combat the offensive revolution.