Through seven weeks, there have been six different teams to sit atop ESPN’s Football Power Index (FPI) after having a total of four No. 1 teams in 2015. While critics may point to FPI’s volatility, the number of changes before the midpoint of the season illustrates the state of the NFL.
Take a look down the standings and you will see that nearly every team in the NFL is in some way flawed.
Below is a chart mapping the contribution of each unit to its team's net scoring margin on offense and defense. This is captured with ESPN’s expected points added statistic, which accounts for the context of every play and how each play contributes to the unit’s ultimate goal of scoring (on offense) or limiting opponents’ points (on defense). Read more about EPA here.
For the most part, the EPA ranks by unit are largely what is to be expected. The Dallas Cowboys, Atlanta Falcons, Detroit Lions, New Orleans Saints and New England Patriots rank in the top five in offensive EPA per game, while the Minnesota Vikings, Philadelphia Eagles, Arizona Cardinals, Denver Broncos and Buffalo Bills are in the top five defensively.
What may be surprising, however, is that most teams that rank high on one side of the ball are among the least efficient on the other. The top eight teams in offensive EPA have an average defensive rank of 24.6, and only one (New England Patriots) ranks higher than 15th defensively. Similarly, the eight best teams in defensive EPA have an average offensive rank of 21.8, and only one (Buffalo) ranks higher than 15th offensively.
Let’s run through a few notable outliers:
The Vikings lead the league in defensive EPA but rank 28th on offensive. Their defense has added 59 points towards their scoring margin, while their offense has cost them 17 points this season.
The Falcons, on the other hand, have the most offensive EPA in the league (Cowboys are better on a per-game basis) but rank 28th defensively.
The Lions have joined the Saints as a team with an explosive offense and Swiss cheese-like defense. Their offense is adding nearly 10 points per game to their net scoring margin (third in the NFL), while their defense is costing them about 11 (worst in the NFL).
The Baltimore Ravens are the opposite of the Lions with the eighth-ranked defense and worst offense.
Overall, no team ranks in the top nine of both offensive and defensive EPA. The Patriots are closest to being the most complete team with the fourth-most efficient offense and 10th-most effective defense. It’s no coincidence that the Patriots also sit atop ESPN’s FPI.
The next question is whether this year is unique. In seven of the past 10 seasons there had been at least one team ranked in the top nine in offensive and defensive EPA in every single week of the regular season. In two of the three outlier seasons, there was a team in the top nine on both sides of the ball in all but one week. The biggest outlier during that time was 2008, and that year the Pittsburgh Steelers (great defense and flawed offense) beat the Cardinals (great offense but flawed defense) in Super Bowl XLIII. Chances are we will see another Super Bowl like that this season.