Super Bowl LVII Preview: An Analytical Guide to Sunday's Big Game
It all comes down to this.
One final NFL game for the 2022-23 season, and despite the twists and turns, it's a pretty fitting conclusion to the season.
Out of the NFC, we have the Philadelphia Eagles, a team that dominated the regular season until a late-season injury to quarterback Jalen Hurts. His postseason return has really helped prove the gap between the Eagles and the middle of the NFL. That's why the Eagles hold the only double-digit nERD score (i.e. expected point differential against an average opponent at a neutral field) in the NFL at 11.13.
And then from the AFC, we once again have the Kansas City Chiefs, who have overcome a lack of wide receiver depth, a rotation at running back, and a middling defense to reach the Super Bowl for the third time in four years behind superstar quarterback Patrick Mahomes -- in spite of an ankle injury that put his AFC Championship game status in question. The Chiefs have played their way to the second-best nERD score in the NFL (9.62).
That means that -- mathematically -- we're getting the two best teams in the NFL squaring off for Super Bowl supremacy, according to our nERD metric.
The elite output for each team has made this matchup a tight one. According to the NFL odds at FanDuel Sportsbook, the Eagles are 1.5-point favorites, and the total is set at 50.5.
I'll reference numberFire's Net Expected Points (NEP) metric throughout this piece, You can read more about NEP in our glossary. In case you're new to an expected points model, don't worry. It's pretty straightforward.
Here's an example.
In almost every case, we'd think of a 10-yard gain offensively as a better play than a 2-yard gain. However, if the 10-yard pickup comes on 3rd-and-20 and the 2-yard pickup comes on 3rd-and-1, which matters more? The drive extender or the play that earned five times as many yards but led to a punt?
An expected points model accounts for those play-by-play discrepancies and helps to show the underlying performance of a team.
So, anyway, that's NEP in a nutshell, and it's how we define and rank teams and players at numberFire.
I'll also reference NextGenStats' Expected Points Added (EPA) model, as well.
Here's how each team ranks in opponent-adjusted offensive and defensive efficiency across the main categories, via numberFire's NEP model.
Okay, so, not only are these the two best overall teams in football by nERD, but these are also the top two offenses in the NFL this season.
Each team ranks top eight in both passing and rushing, and the top individual passing unit (Kansas City) and the top individual rushing unit (Philadelphia) are represented in the Super Bowl.
As you'll note from there, the defense really is the separator with the Eagles holding a top-six unit and the Chiefs ranking just below the league average at 19th overall.
Neither rush defense is particularly good, and we're seeing the Eagles slot in with the best adjusted pass defense in football.
Do we just chalk this up to the Eagles having the advantage because of defense? Maybe.
But there's a lot more to dig into.
Adjusting Quarterback Play
Unsurprisingly, Patrick Mahomes led the NFL this season (among 33 quarterbacks with at least 250 drop backs, including the playoffs) in Passing NEP per drop back (0.31), more than five times better than the NFL average of 0.06.
That number for Jalen Hurts is a very respectable 0.15, which ranked him ninth in that 33-quarterback sample.
When you adjust every single drop back these two had against the opponent faced, Mahomes has accrued 0.25 Passing NEP per drop back over expectation. Put another way, if he played to opponent level on every pass, he'd have had a league-average output of 0.06. He simply dominated once accounting for opponents.
Remember: the Eagles are the top adjusted pass defense in football. But in three games against teams in the top seven in adjusted pass defense, Mahomes averaged 27.3 completions on 39.3 attempts for 367.7 yards and 3.0 touchdowns -- for 0.46 Passing NEP per drop back and a 58.7% passing success rate.
It's nearly impossible to overstate how good Mahomes has been even when accounting for opponents or when looking specifically at his toughest matchups.
What about Hurts?
One knock you may have on the Eagles is their playoff path. They virtually wrapped up a bye after Week 15 (I know it wasn't exactly the case, but they were sitting pretty entering Week 16). They then played the New York Giants, who were a weak playoff team, and then benefitted from the unfortunate quarterback injuries suffered by the San Francisco 49ers in the NFC Championship game.
Is that masking Hurts and this offense against good teams?
Maybe. Maybe not.
Against all teams this year, Hurts has a Passing NEP over expectation per drop back rate of 0.10. Against teams that are 8th through 18th in adjusted defensive Passing NEP allowed (so, somewhat similar to the Chiefs at 12th overall), Hurts has averaged 0.13 Passing NEP per drop back (with a per-game line of 19.0 completions, 29.0 attempts, 226.5 yards, and 2.3 touchdowns) in four games.
He's been a bit more sensitive to the matchups faced than Mahomes has.
Then again, the Eagles' offense is built around the run game. We'll get there soon, but let's next look at pressure and how the quarterbacks handle it.
Handling the Pressure
We know the Eagles can get to the quarterback. They rank second in pressure rate, according to NextGenStats, and Mahomes may not be as mobile by the Super Bowl as he historically has been due to his ankle injury.
In terms of pressure rate allowed this season (including playoffs), the Chiefs (26.1%) were a bit better than average (28.0%), and among 35 qualified quarterbacks, Mahomes ranked 5th in EPA per drop back against pressure.
Hurts and the Eagles surrendered pressure on only 22.8% of drop backs (sixth-best), and the Chiefs are just middling in pressure rate defensively (17th). But in the event that they do get in the backfield, we could see the game decided on a few key pressures.
Jalen Hurts ranks 24th in EPA per drop back on pressured plays among those 35 qualified quarterbacks, and that includes the 30th-best success rate on such plays.
Here's a snapshot of each quarterback's EPA per drop back versus pressure and from a clean pocket -- as well as the NFL averages and their ranks.
|Patrick Mahomes||0.41 (1st)||-0.32 (5th)|
|Jalen Hurts||0.25 (6th)||-0.66 (24th)|
I'm sure even the most diehard Eagles fan would acknowledge a gap between these two quarterbacks. In fairness to Hurts, when he has had a clean pocket, he's been great. It's the pressure data that is a mite concerning.
What about the AFC Championship specifically for Mahomes under pressure? How did he fare with the ankle injury being what it was?
Well, on 16 pressures, he was sacked 3 times; on his 13 pass attempts, he was 7 for 13 for 113 yards and 1 touchdown, good for -0.22 EPA per drop back (well above the league-wide average of -0.50 on pressured drop backs).
We'll hear a lot about the Eagles' pressure rate versus Mahomes' mobility, but if the Chiefs get to Hurts, that could decide the game all the same.
Could the Run Games Take Over?
As we already laid out, neither rush defense is particularly good, as both are outside the top 20 in Adjusted Defensive Rushing NEP per play allowed on the season.
Knowing the Eagles' run-heavy tendencies, they will gladly take advantage of it, but would Kansas City do the same to avoid throwing against the league's best adjusted pass defense?
Well, first of all, let's pump the brakes on the assumptions because they may not bear out the way we think.
Let's take a look at each team's pass rate over expectation (as measured by nflfastR's play-by-play data). Pass rate over expectation accounts for things like time remaining, win probability, down-and-distance, and more to figure out which teams are throwing more or less than an average team would.
On the entire season to date, the Chiefs have posted the only double-digit pass rate over expectation at +11.1%. In an abnormally run-heavy season, the average pass rate over expectation was -2.2% for all NFL teams.
A team that we definitely think of as run-first is the Eagles. Their pass rate over expectation, however, was -2.8% -- just below the NFL average.
But let's go back to the reality of each team facing beatable rush defenses. Has either team used their efficient rushing offense to carve up weak rush defenses when given the chance?
Yes and no.
It was actually more of a "yes" for the Chiefs. Their pass rate over expectation against bottom-12 rush defenses was +7.3%, so down 3.8 points from their full-season average.
For the Eagles, their pass rate over expectation actually climbed to -1.2% against bad rush defenses.
If past precedent is any indicator, these two teams should -- more or less -- stick to their game plans even with the ground matchup in front of them.
But Then the Pass-Catchers Will Make the Difference, Right?
In theory, they should.
The Eagles' on-paper trio of A.J. Brown, DeVonta Smith, and Dallas Goedert stands far above Travis Kelce and whichever two pass-catchers we consider next in line for the Chiefs (likely JuJu Smith-Schuster and -- after that AFC Championship game -- Marquez Valdes-Scantling) by name value.
Statistically? Not so much.
It's incredibly hard to isolate receiver performance from quarterback play, but that's okay because we don't have receivers out there without quarterbacks. And with that being the case, the Chiefs can match up with the Eagles.
Here is how the team's primary pass-catchers fare, ranked by Reception NEP per target. Ranks are among 137 players with at least 50 targets across the regular season and playoffs.
This is super close overall when we look at per-target efficiency, and there's effectively no difference in targets thrown to Brown, Goedert, Smith-Schuster, Kelce, Valdes-Scantling, and Smith.
Of course, the average target depth numbers and success rate marks are a bit different across the board, but over the long haul, Mahomes has gotten about as much out of Kelce and his teammates as the Eagles have gotten from two second-round picks (Brown and Goedert) and a first-round Heisman winner (Smith).
I feel the need to clarify that pointing this out is incredibly different than stating that the Chiefs' best three can match the Eagles' top three if the quarterback situation was changed.
All it's showing as that Kelce, Smith-Schuster, and Valdes-Scantling have been pretty great. It's a testament to Mahomes and this offense for figuring things out in order to give this game six top-32 performers in per-target efficiency.
Hey, it's the Super Bowl. Special teams can easily play a big part in this week's outcome.
Here's how each unit has fared in Special Teams NEP so far this season
|Kansas City||9.49 (27th)||67.62 (31st)||-58.13 (32nd)|
|Philadelphia||3.75 (31st)||19.57 (13th)||-15.82 (23rd)|
Let's start with the Chiefs, who have the worst cumulative special teams unit in football by NEP. Part of that can be chalked up to the fact that -- among 30 kickers with at least 25 field goal attempts -- Harrison Butker ranks 27th in Field Goal NEP per attempt (0.15).
Jake Elliott (0.51) ranks 16th.
NextGenStats' field goal percentage over expected shows a similar gap. The league-average field goal percentage over expectation this year was +10.7% (which can be attributed to taking a long-term sample to derive the metric and comparing past kicks to today's more efficient kickers).
By that measure, though, both were still below average with Elliott at +11.0% and Butker at +7.2%.
In terms of kickoffs, Elliott and Butker separate a bit from the league average with regard to hitting the end zone. Elliott (79.8%) is well above average (67.1%) there. Butker (73.8%) also beats the NFL average in that department.
The punter battle seems a little more one-sided.
The Chiefs' Tommy Townsend ranks fourth in punt average on punts from his own territory (61.5 yards) with the Eagles' Brett Kern ranking last among all punters at 50.7 yards.
Townsend ranks second in hang time on such punts (4.76 seconds). Kern owns the lowest hang time on such punts (3.76). Even excluding the NFC Championship game to get the wire ball out of the sample, Kern's marks (51.2 and 3.85, respectively) are league-worst outputs.
Analytically Comparable Teams
At numberFire, we can dig into our database (back to 2000) and see which historical teams are most similar to current teams.
Here are each team's top-five comparable squads and their results.
|2021 Chiefs||Lost AFC Championship
|2017 Saints||Lost Divisional Round
|2009 Colts||Lost Super Bowl
|2008 Commanders||Missed Playoffs
|2004 Eagles||Lost Super Bowl
|2017 Jaguars||Lost AFC Championship
|2011 Saints||Lost Divisional Round
|2009 Saints||Won Super Bowl
|2007 Patriots||Lost Super Bowl
|2019 Ravens||Lost Divisional Round
Boy, that's a pretty tight dispersion on comparable Chiefs teams with a much wider range on the Eagles.
numberFire's algorithm views this game as about as close as can be with the Eagles 50.9% likely to win.
Notably, in five of the six most comparable games to this one in numberFire's database, teams representing the Eagles won and covered.
In total, teams representing the Eagles are 15-10 straight up in those historically comparable games as well as 14-11 against the spread. Of the 25 games, 14 of them hit the under, too.
The projected final score, via numberFire's algorithm: Eagles 28.2, Chiefs 27.9.
It doesn't get much tighter than that.