Hmm, this may have to do with averaging in bad teams that score very little. There are many articles on increased offense in the nfl even beyond just recovering last year's dip.
Here's one:
http://www.espn.com/nfl/story/_/id/25459151/nfl-2018-offensive-scoring-explosion-numbers
For the first time in the NFL's 99-year history, two teams scored 50 points in the same regulation game last month. The
Los Angeles Rams' 54-51
victory over the
Kansas City Chiefsunderscored a season-long explosion of offensive production, a trend that has energized fans and coincided with a notable rise in
television ratings.
Through the first 13 weeks of the 2018 campaign, the NFL is averaging more points (47.8), yards (718.4) and passing touchdowns (3.5) per game than at any similar point in its history. Expected points added (EPA) -- a
measure of each play's change in net point advantage for the offense, based on down, distance and yard line at each snap -- has increased nearly 1,200 points from 2017, a massive jump.
The numbers represent a course correction after a one-year dip last season, but the roots reveal boundless opportunity for future expansion. NFL offenses have enjoyed a steady rise for 40 years, ever since the league adjusted a series of rules in 1978 to end the
"dead ball" era and encourage more scoring. But 2018 has produced a sharp spike even beyond that trend.