Offense is kind in the modern NFL, but that doesn't mean defense is altogether irrelevant. Because while offense has a greater effect on overall team performance -- and is more consistent year over year -- than defense, you still need to put up some resistance in order to actually win football games.
For that reason, we're going to rank the league's defenses now that the player-acquisition portion of the offseason is mostly over. Rather than go through every team from 32-1 on this side of the ball like we did on offense, we're going to group the teams by how likely they are to finish the year among the league's top 10 defenses.
Without further ado ...
Atlanta Falcons, Detroit Lions, Houston Texans, Jacksonville Jaguars, New York Giants, New York Jets, Seattle Seahawks
None of these teams finished last season in the top half of the league in either EPA per play or Football Outsiders' DVOA. Only the Seahawks, Giants, Texans, and Falcons finished above-average in any of yards per play (Seattle, Giants), points per drive (Seattle), opponent's turnover rate (Giants, Houston, Atlanta), and the share of opponent drives that ended in a touchdown or field goal (Seattle). None of them ranked better than 10th in any of those categories.
The most notable talent additions for any of these teams are rookies: Travon Walker in Jacksonville, Aidan Hutchinson in Detroit, and Sauce Gardner and Kayvon Thibodeaux in New York. Even if those players contribute at a high level right away, it seems unlikely to make up the difference between where these teams stood, and the top 10 in the NFL. It's possible some of these teams could work their way to slightly below-average on defense rather than awful, but even above-average might be a bit of a stretch.
Carolina Panthers, Chicago Bears, Kansas City Chiefs, Tennessee Titans
The Panthers began last season on fire defensively, but slowed over the second half of the season. They lost Haason Reddick in free agency and don't have a ready-made replacement. Their secondary should be a strength but it's tough to see the front being good enough to push them toward the top 10. Chicago was a disaster defensively last season, and while new head coach Matt Eberflus and a couple of early draft picks should help, the trade of Khalil Mack robs the Bears of their best pass-rusher.
Kansas City used four of its first five draft picks on the defensive side of the ball, so perhaps we're being a bit unkind to the Chiefs here, but even while forcing a ton of turnovers last season they still finished outside the top 20 in EPA per play, DVOA, yards per play, and points per drive.