Defense does not win championships and is highly volatile

Playing around with some NFL data and used some code from Ben Baldwin(great twitter follow and Seattle columnist for the Athletic) to generate 3 graphs that I believe tell a compelling story. The graphs map team EPA for Offense and Defense over the 2017, 2018, and 2019 seasons, Top right is best, bottom left worst. Top Left is bad offense, good defense. Bottom Right good offense, bad defense.

EPA Explained

What I want to focus your attention on are the defensive outliers of each year:

2017: Jaguars
2018: Bears
2019: Patriots

Notice the massive decline in Defensive EPA(negative EPA for defense is better) for the Jaguars in 2018 and the Bears in 2019. I think alot of this is turnover based and tds off turnovers. But the point is that replicating an outlier performance for defense is volatile.

The Rams meanwhile have stayed relatively consistent in this measure.




So, I would expect the Whiners defense to come back to earth or regress to the mean this next season. Also, the Rams have to get the offense back on track.

Also, focusing in on the quadrants for 2019 note the dearth of quality Qbs in the 3rd Quadrant(bottom left). Stafford and Baker are the best Qbs here, while there are alot of 'star' rbs--McCaffrey, Saquan, Fournette, Chubb, Mixon.