The 5 Worst NFL Defenses Through Week 9

Who are the five least efficient defenses through the first nine weeks of the season?

NFL purists will likely disagree, but I love a bad NFL defense.

Bad defenses are what turn NFL games into track meets and often what allow single-game records to be broken. One only needs to look at Week 8's Saints-Giants 52-49 game to see what I mean.

But the value of a bad defense goes beyond entertainment value. It gives those in daily fantasy leagues opposing teams to target and those in season-long leagues looking ahead to their fantasy playoffs matchups to look out for.

So what does a bottom-ranked defense look like?

As you might expect, the teams that rank in the bottom of the league based on our strength of schedule-adjusted defensive Net Expected Points (NEP) metrics are notoriously bad against the pass. In other words, because passing is far more efficient than running the ball -- it's just easier to complete a 20-yard pass than to pull off 20-yard run -- it's no coincidence that the teams ranking at the bottom of the league are also the ones that give up the most points through the air on a per-play basis.

For those unfamiliar, what NEP measures is a given play's contributions to a team's chances of scoring above or below expectation. In the case of defenses, if a unit makes a play that decreases the opposing offense's chances of scoring below expectation, they receive credit for that in the form of a negative score proportional to the magnitude of that given play.

So with all that being said, who exactly are the worst defenses in the NFL so far based on our NEP metrics?