Similar to inches, the numbers you need in football are all around you.
Over the years, football has become a game of numbers. Turn on any broadcast, and it will not take long for the word “analytics” to reach your ears through the television. Whether on a fourth-down decision, the discussion of metrics such as Expected Points Added (EPA) or Completion Percentage Over Expectation (CPOE) or in some other fashion, numbers have become commonplace in today’s NFL.
The Seattle Seahawks clinched the NFC West and the No. 1 seed in Week 18, and head to the Divisional Round with one of the league’s best defenses on their side.
A unit that has flipped the numbers on their head.
The numbers here are not rooted in metrics — although those speak to Seattle’s success on the defensive side of the ball — but rather in personnel. Over the past few seasons in the NFL, offenses have gotten bigger with their personnel packages. Take the Los Angeles Rams for example, who turned the league on its head with their increased used of 13 offensive personnel: One running back, one wide receiver, and three tight ends. While 11 personnel (three wide receivers) remains the norm across the league, the push-and-pull of schematic design has started to swing in the other direction.
Simply put, as offenses got lighter with their personnel groupings, defenses adjusted with more nickel and dime packages. Now, teams are getting bigger in response, such as the Rams’ example above.
Some defenses have leaned into more base packages.
The Seahawks had five or more defensive backs on the field for 92.5 percent of their defensive snaps during the regular season, the most in the league according to NFL Next Gen Stats. But beyond the personnel on the field, is the manner in which head coach Mike Macdonald deployed his defense. Instead of dropping a safety down in the box to help protect against the run, for the most part Seattle has stayed with two-deep coverages, keeping both safeties deep, leaving Macdonald trusting his defensive line up front at the point of attack, and his secondary to run the alley after the snap, against the run.
That has worked, to an impressive degree. Despite playing more nickel and dime than any other team this year, the Seahawks held opponents to a league-low 3.7 yards per carry, all while running their streak of not allowing a 100-yard rusher to 26 games. That streak is both a franchise record and the longest active streak in the league.
So, how has Seattle been able to do this?
Thanks to talent at all levels of their defense.
It starts up front, with their rotation of defensive linemen that includes Leonard Williams, Jarran Reed, Byron Murphy II, DeMarcus Lawrence, Uchenna Nwosu, Derick Hall, and Boye Mafe. Players on the interior such as Murphy, Williams, and Reed swallow up blockers, despite often being outnumbered at the point of attack. But their willingness to do the dirty work creates opportunities for linebackers Ernest Jones IV and Drake Thomas at the second level, and players such as defensive backs Devon Witherspoon and rookie Nick Emmanwori who are not afraid to come downhill against the run.
Take this play from Seattle’s Week 18 win over the 49ers. San Francisco comes out with 21 offensive personnel: One tight end, two running backs (Christian McCaffrey and Kyle Juszczyk) and two wide receivers.
Seattle counters with five defensive backs, and they show both safeties deep before the snap. They are quite literally daring Kyle Shanahan to call a running play.
Which he does, and it goes for just a two-yard gain:
Stopping this run starts up front, with the pair of double-team blocks on Williams and Murphy. While the 49ers are able to contain Williams, Murphy holds up against his double just enough and resets after initial contact, giving him a path to McCaffrey. Add in Emmanwori, who slid down into the box almost as a third linebacker, and the 49ers are held to a two-yard gain.
Or take this play, where the defensive linemen all slant to their left, while Jones loops around over the top:
This is a 2nd-and-5 play, and the 49ers have a pair of tight ends in the game. But Seattle stays true to their numbers by staying in nickel, and they hold this play to a one-yard gain.
Here is one more example of this in action, as the 49ers come out for this 1st-and-10 play on their own 9-yard line with 21 personnel, as both Juszczyk and McCaffrey are on the field, along with tight end George Kittle. The Seahawks again stay with nickel personnel, and with the formation up front even with Seattle dropping a defender into the box, there are simply more gaps than there are defenders.
This should be a win for San Francisco.
But watch Murphy on this play, who covers two gaps with his technique. As McCaffrey takes the handoff he aims for the A-Gap but Murphy has slid into that gap and is controlling his blocker in McCaffrey’s path, so the running back bends the run to the backside.
That is when Murphy, who has kept eyes on McCaffrey the entire time, disengages and slides into the other gap, stopping this run before it gets going:
These three plays have highlighted what the Seahawks defense has been able to do against the run, even with the numbers tilted against them. But where their reliance on nickel and dime packages truly stands out is against the pass. As noted above, numbers are part of the game these days, starting with Expected Points Added.
Here is where the Seahawks stand in terms of EPA against both the run and the pass:
While the Seahawks are the league’s best in terms of Rush EPA/Play allowed, they are no slouch against the pass. Numbers help there too, because with extra defensive backs on the field, they are able to cover better in the secondary.
But the most curious part of how Seattle has crafted their defense is this: They get pressure without blitzing, which keeps the numbers in the secondary in their favor. This season, the Seahawks pressured opposing passers on 26.1% of dropbacks, sixth-most in the NFL. They racked up 47 sacks, seventh-most in the league.
They did that while blitzing on just 19.3% of their snaps, the seventh-lowest blitz rate in the league.
That is the magic serum for any defense: Pressure without blitzing, and winning the numbers game in the secondar.
Take this sack of Brock Purdy from Week 18:
Facing 3rd-and-3, the 49ers put Purdy into an empty formation and release five receivers into the route concept, including McCaffrey who chips Lawrence before releasing into his route. But Seattle drops seven into zone coverage against the five receivers, and every route or throwing lane is taken away from Purdy.
Eventually, time runs out. With the numbers working against Purdy, he has nowhere to go with the football, and the pocket finally breaks down around him.
Or take this play against the Carolina Panthers from Week 17, where again the Seahawks get home for a sack with four:
Of course, this concept allows Macdonald to perhaps do what he does best: Dial up simulated pressures. On these plays Seattle still rushes four, but the pre-snap look from the defense leads to post-snap problems for the offense. This sack against the Minnesota Vikings is one example, as the Seahawks show blitz with seven defenders on the line of scrimmage, but only bring four after Max Brosmer:
One of the ways Seattle likes to do this is by dropping Mafe off the edge into coverage, and blitzing from the other side, as they do here against the Arizona Cardinals:
The Seahawks have found ways to turn the numbers that are all around a defense into their favor.
That has them on a path to the Super Bowl.
