Yesterday, I looked at the top offenses in the NFL. Today, the top defenses, as I did last year. Let’s begin with pass defense.

Pass Defense

The Bears, as you would suspect, ranked as the best pass defense in the NFL. We use the same formula to measure pass offenses and pass defenses, and Chicago’s pass defense was nearly a full adjusted yard per dropback than any other team.

(Passing Yards (net of sack yards lost) + Passing Touchdowns * 11 + First Downs * 9 – Interceptions * 45) divided by (Attempts + Sacks)

The Bills, Ravens, Vikings, and Jaguars were all top-5 pass defenses; three of them missed the playoffs, and a fourth nearly did. That’s pretty remarkable but don’t misunderstood the value of a good pass defense. The bottom 5 pass defenses all missed the playoffs, and none came particularly close.

Rush Defense

We will use the same formula for rushing defense as we did for rushing offense. Here, the Broncos lead the way, while the Bills, Chargers, and Patriots had the worst three rushing defenses.

(Rushing Yards + Rushing TDs * 11 + Rushing First Downs * 9 – Kneel Yards Lost) divided by (Rushing Attempts – Kneels)

The Bears defense was remarkable this season, and ranks 2nd in this metric only to the Texans. Houston allowed just 3.4 yards per carry and that number wasn’t inflated by a bunch of opposing kneels; the Texans joined the Bears as the only two defenses that allowed first downs on only 20% of opposing runs in 2018.

Defensive Strength

Let’s put it all together, again using a 65% weight on pass defense and a 35% weight on rush defense. The Bears were, by a good measure, the best defense in the NFL. Perhaps the most surprising note: all four teams in the AFC South ranked in the top 9 in defense (note that this is without SOS-adjustment, which would hurt the division).

The Chiefs, who ranked 26th, were the only defense in the bottom 10 to make the playoffs. And that required a historic performance from the offense.

Team Strength

With grades for each four units, we can also put together team grades. I weighted offense and defense equally, and subtracted the team defensive efficiency rating from the team offensive efficiency rating to derive a team rating.

By this measure, the Bears were the best team in the NFL this year, on the strength of the best defense in the NFL despite a below-average offense. That says a lot about the lack of dominant teams in 2018. The Chargers were the only team to rank in the top 8 in both offensive and defensive efficiency, which is why Los Angeles is our number two team. The Patriots are the only other team to rank in the top 10 in both offense and defense.

The Bears, Chargers, Chiefs, Rams, Saints, Ravens, Patriots, and Texans are the top 8 teams by this metric. All 8 made the playoffs. The next two teams missed the playoffs on the final day of the regular season, and had the best records in the AFC and NFC of the non-playoff participants (Minnesota and Pittsburgh).

The other four playoff teams ranked 11th (Indianapolis), 13th (Seattle), 14th (Philadelphia) and 15th (Dallas). Those are four of the weaker teams in the playoff field, and the Cowboys made the playoffs courtesy of an unsustainable 8-2 record in games decided by 7 or fewer points. In other words, for a measure that doesn’t tell you anything about points scored or points allowed (other than by incorporating touchdowns as part of adjusted net yards), this methodology does a remarkably good job of identifying the best teams.

And the worst teams? It identifies them well, too. The Cardinals, Jets, Raiders, Bengals, Redskins, Dolphins, Lions, and Bills were the 8 worst teams by this mark.

Finally, let’s close with a pretty neat graph. This shows where each team ranked in each of the categories, and is color-coded (blue = strong; red = weak). You can see that Chicago ranks 1st entirely because of the team’s great defense, while the Chiefs are even more one-sided the other way.

What stands out to you?