Summary of “Why The NFL Can’t Rely On Defense”

A week later, Joey Bosa and the emerging Chargers defense were dismantled by the Patriots, and the Cowboys – perhaps the best defensive team left in the divisional round based on their end-of-season play – lost to the Rams.
Extracting the strong defensive teams with relatively weak offenses led to historically exciting playoff football, producing two overtime games in the championship round for the first time in NFL history.
Teams are more reliably good – and bad – from game to game and year to year on offense than on defense.
Home teams win about 73 percent of their games when they are plus-1 in turnover differential, according to data from ESPN’s Stats & Information Group, and the home team win rate climbs to more than 86 percent when it’s plus-2 or better.
Despite their clear importance, the number of turnovers a team creates in one season has no bearing on how many turnovers the team will create in the next.
Casting even more doubt on their ability to field an elite defense in back-to-back years, Chicago also lost its defensive coordinator, Vic Fangio, who left to become the head coach in Denver, further destabilizing the strength of the team.
Philadelphia led the league in QB hits but not sacks Total quarterback hits, sacks and expected sacks for teams’ defensive lines in the regular season, 2018.
If these teams generate similar pressure next season, we shouldn’t be surprised to see their sack totals rise just based on reversion to the mean.

The orginal article.