In a Post-Defense NFL, the Chicago Bears Shine
As Optimum Scouting has already covered this season, the 2018 NFL season may be a pivot point where the fourth era of modern passing efficiency begins. Excluding teams (Browns, Jets, Cardinals and Bills) which have played rookie quarterbacks for a long period of time, which we know is almost completely different from veteran quarterbacking, the 28 veteran-led passing offenses in the NFL average an Adjusted Yards per Attempt (AY/A) of 7.3 yards. To put that into perspective, that’s a half-yard better than 2017, which adds up when you account for the fact that this is a per attempt stat.
Fundamentally, we are in a different era of passing offenses...which equally impacts the sliding scale of defensive play. Within the context of this sliding scale, there is no doubt who is the most dominant defense in the NFL this year: the Chicago Bears.
The league-wide Adjust Net Yards per Attempt (ANY/A) in the NFL, which is essentially AY/A that includes sacks and sack yards, is 6.5. Chicago’s season ANY/A of 4.7 means that their defense is roughly two yards more valuable than the NFL average for every pass play that they have faced this year. ANY/A Value, which measures how many yards above or below average a defense is playing, paints the Bears as the clear defensive juggernaut in the NFL through 11 weeks.
As you can see, Chicago’s season mark of +769 yards of value is 83% more valuable than the second-best pass defense in the league (Baltimore Ravens.) The 29th-ranked New Orleans Saints (-340 yards) are closer to the second-ranked Ravens than Chicago is to the NFL average. This season should mostly be remembered as one where defensive passing efficiency has basically been homogenized. There is essentially one good defense (Chicago), three awful defenses (Detroit, Oakland and Tampa Bay) and massive upper to lower middle class of defensive play.
If you extrapolate Chicago and Baltimore’s season marks through 16 games, the Bears are projected to finish with +1,227 yards of value and the Ravens are projected to finish with +669 yards of value. Below is a chart of how the first-ranked and second-ranked defenses each year have stood at the end of the regular season since 2004, when defensive pass interference enforcement ushed the NFL into a new era of passing efficiency:
This is about as clear as it gets. At their current pace, the Ravens, who can at the moment claim the title of the "second-best pass defense in the NFL", will rank as the second-worst “second-best” defense in the NFL since 2004 (ahead of just the 2016 New York Giants.) Meanwhile, the 2018 Chicago Bears are on schedule to fall behind just the 2008 Pittsburgh Steelers, 2013 Seattle Seahawks and 2015 Carolina Panthers among the most valuable pass defenses since defensive pass interference enforcement pushed the NFL into a more pass-friendly league. It is worth noting that the 2008 Steelers and 2013 Seahawks won the Super Bowl in those respective seasons, while the 2015 Panthers made it to the Super Bowl but lost to the Denver Broncos. The Broncos had the second-ranked pass defense in the NFL in 2015.
In this era, stretching a decade and a half, there has never been as clear of a number one defense separating from the pack as 2018 Chicago. Assisted by the fact that their quarterback Mitch Trubisky is playing on a rookie deal, the Bears aggressively went after pass-rusher Khalil Mack, drafted linebacker Roquan Smith with a first-round selection and re-signed cornerbacks Kyle Fuller and Prince Amukamara on contracts collectively worth $87 million this offseason. The Bears have caught lightning in a bottle and it has paid off big time.
At the moment, FiveThirtyEight gives Chicago the sixth-best chance (71%) of winning a division title in the NFL on top of the sixth-best chance (87%) of making it to the playoffs. These projections, and their 7-3 record, would not be possible if it was not for the fact that they have the only meaningful defense in the league.