Ever since Michael Lewis’ bestselling book, Moneyball: The Art of Winning an Unfair Game, hit the shelves in 2003, the idea of production value in sports has been much more present for us fans and analysts of these games. Famously, Lewis followed the Oakland Athletics baseball team to determine how they constructed winning seasons with less than one-third of the payroll that the mighty New York Yankees had. With this, the economics terms “market inefficiency” and “cost-benefit ratio” have become part of an evaluation standard for team performance, from Major League Baseball to Major League Soccer, and everything in between.

One of the most difficult sports to evaluate in terms of how much you get for how much you spend, however, has been the NFL. In such a colossal team sport, it’s hard to know where the quarterback’s arm and the receiver’s hands begin. For NFL defensive players and units it’s even tougher.

The Big Uglies Under the Microscope

Today we’re examining the defensive line and linebacking corps for every team in the NFL in these terms, and the adage that sticks out to me here is “Disruption is production”. In its simplest form, this means that just because a player didn’t tally a tackle or a sack on a play, doesn’t mean they didn’t affect the outcome of that play, making it much tougher to attribute success to any one player. This is why the defensive “front seven” is a challenging beast to evaluate: one Jadaveon Clowney may not tally high production, but his play opens up the field for his teammates.

Fortunately, through our Net Expected Points (NEP) – a measure of how much a defense diminished their opposition’s chances of scoring on any given drive – metric here at numberFire, we will compare the production of every NFL “front seven” and determine exactly who got the most bang for their buck in the box (say that five times fast). Specifically, we will address Adjusted Defensive Rushing NEP, which is a measure of how well a defense defended the run, adjusted for the overall effectiveness of that running game. In essence, if a defense performs well against a good rushing team, that means a lot more in adjusted value than a good performance against a bad rushing team. Albert Haynesworth is out of the league, so how can anyone’s cost-benefit ratio be that bad, right?

League Ledger

One important thing to note as we look at the below chart is that, for Defensive NEP, negative numbers are a good thing. We want a defense to be preventing expected points, not allowing them. For instance, the Denver Broncos were our top run defenders with a -51.45 Adjusted Defensive Rushing NEP, which meant they held their opponents' run games 50 points under what they should have over the course of the season. In contrast, the historically awful Chicago Bears put up a 73.73 Adjusted Defensive Rushing NEP, allowing more than 70 points more than they should have to teams on the ground all season. When you compare the salaries of these teams, though, it becomes even more fascinating because a team like the Seahawks actually spent nearly $2,000,000 less than the Bears.

The table below shows the entirety of the league's teams, sorted by their Adjusted Defensive Rushing NEP, the combined payroll of defensive linemen and linebackers, and their salary ranking (1st is the most expensive, 32nd the least).

Exactly half of the league was above expectation defending against the run, and half was below. What can we learn from this, then?

Money Doesn’t Matter...: Among the league’s cheapest front seven units were three of the top five in the league in Adjusted Defensive Rushing NEP (Denver, Philadelphia, and New York Jets). Conversely, three of the most costly units also held the ignominious distinction of being in the six worst against the run: Chicago, Miami, and Green Bay.

...Until It Does: Yet, two of the bottom front sevens against the run were also among the cheapest in the league, as well: San Diego and Atlanta. And, of course, three of the best units in Adjusted Defensive Rushing NEP were also the costliest: St. Louis, Seattle, and Baltimore. It seems that there is little relationship between spending and a high ranking, as there is no clear trend across any of this data.

Bargain Bin Rush Reduction: Interestingly, Oakland should maybe not be lambasted for their discount approach to defensive construction. With a 32nd place ranking in Front 7 Salary and just under one-third of the spending of the historically bad Chicago Bears, they still mustered a middle of the pack 18th place ranking in the defensive metric. Joining them in discount mediocrity were the Tennessee Titans (19th against the run, 31st in salary), who will become more expensive in 2014 after signing linebacker Wesley Woodyard among others, but it remains to be seen if they will be more effective.

Offense is the Best Defense?: The two most cost-efficient defensive units belong to the same teams as the most hyper-quick, scary-effective offenses in the league. That would be the Denver Broncos and Philadelphia Eagles. When your big bruisers are forced to stay on the field for long periods of time because your offense scores so fast, one would expect they’d get winded and ineffective. However, it seems that these teams’ focus on paying for offense and instead cycling through great rotations of cheaper defensive players in their front seven is a workable and valuable tactic. Philadelphia has remained with this, but Denver did go on a defensive spending spree this offseason. Defensive end DeMarcus Ware was the big splurge in the front seven, but this may be a solid tactical calculation on the Broncos’ part. We will see how they fare at the end of 2014.

Traditional Smash-Mouth is Gone: Three of the least-efficient front sevens in cost per NEP are traditional defensive powerhouses in the NFC North in Green Bay, Chicago, and Minnesota. These are also in the top 10 in spending overall on the front seven. Minnesota lost a few of its higher-paid pieces, such as defensive end Jared Allen, in the 2014 offseason, and replaced them with much cheaper rookie options - they should leave this company come next year. Chicago, however, added Allen, as well as former Raiders end Lamarr Houston, meaning they will need a massive rise in production in 2014 to even sniff the top half of the league in efficiency.

Go West, Young Man: The strongest and most efficient division in the league - go figure - is the NFC West. All four of its teams ranked in the top 10 in Adjusted Defensive Rushing NEP. The commitments of Seahawks’ general manager John Schneider and his San Francisco counterpart, Trent Baalke, to building dangerous defenses with players who were discounted in both the market and the draft has clearly played out well thus far.

Where to Go From Here

There is no indication that spending more money or less guarantees defensive success in your front seven. However, it's worth noting that Denver and Philadelphia, the two most cost-efficient and effective defenses, have built their success on the principle of bringing up cheap, young players through their organization and using them situationally to keep them fresh. Big signings like Ware’s seem to be outliers for these organizations, as they prioritize, of course, efficiency over name value.

The balance of power has shifted from the traditional centers of defensive trench warfare in the Midwest and Rust Belt to the West. Teams like the Packers, Bears, Steelers, and others are prioritizing offense in their scouting, which leaves a lot to be desired on defense. Instead of drafting or finding undervalued defensive pieces to fill their ranks, they seem to be trying to spend on impact players. The Seahawks, 49ers, and Rams, however, are three of the younger teams in the league and have had immense success in the draft to keep youth and depth cycling through their organizations.

The main takeaway here is that the fluctuation in defensive value and production on an annual basis seems to make heavy investment in the front seven a losing proposition. Instead, teams should look to infuse their pass rush and run stopping units with depth and youth, rather than overpaying for name value veterans. The game is becoming more and more about speed and efficiency, and the “moneyball” strategy is to find young players and devalued veterans to help your team up front.