Football Outsiders ranks the 30 best defenses over the last 30 years according to DVOA

Earlier today, I shared the two Denver Broncos offensive units that made the DVOA list of the 30 greatest offenses of the last 30 years. Now they are doing the 30 greatest defenses of the last 30 years and the Broncos made the list again, twice.

The 2015 and 2016 Broncos were historically good. One went all the way to dominate defensively in Super Bowl 50, while the other couldn’t drag a historically bad offense into the playoffs.

28. 2016 Denver Broncos

-19.0 percent

Last year's Broncos were even better against the pass than you probably think. Only two defenses in 2016 faced a tougher schedule of opposing offenses. Nine of Denver's games came against the top dozen teams in pass offensive DVOA, although the Broncos also get a bit of an artificial boost because one of those games was against Oakland's backup and third-string quarterbacks. The 2016 Broncos rank as the No. 12 pass defense of the past 30 years, but they get dragged down our rankings in overall defense because they were below average against the run.

The No Fly Zone was so good that even the 27th ranked run defense couldn’t keep this unit off the list of 30 best defenses.

If they had that run defense, they would have ranked a lot more like the 2015 Broncos defense.

5. 2015 Denver Broncos

-28.3 percent

Unlike last year's Broncos, the Super Bowl champions were dominant against both the pass (No. 1 in DVOA with a league-leading 5.1 net yards allowed per pass) and the run (No. 4 in DVOA with a league-leading 3.3 yards allowed per carry). The Broncos put up these numbers against the fourth-toughest schedule of opposing offenses. Denver's issue wasn't too many games against the best offenses, but almost no games against bad offenses; Indianapolis and Cleveland were the Broncos' only opponents to rank 21st or lower in offensive DVOA. Then, like the 2013 Seahawks, they had to vanquish three of the top eight offenses in the playoffs on the way to the Lombardi trophy. Remarkably, Von Miller was the only player on this defense elected to the AP All-Pro first team.

Here is where DVOA gets a little crazy. The 2004 Buffalo Bills came in 4th and the 1991 Philadelphia Eagles came in 1st, yet both teams failed to even make the playoffs. It’s unfathomable that such dominant defenses could not get their teams into the tournament.

Especially since the 2nd and 3rd ranked teams, along with the 2015 Broncos, won Super Bowls. Those teams were the 2002 Tampa Bay Buccaneers and the 2000 Baltimore Ravens.

Even so, that 2015 Broncos defense was remarkable and one that will go down as one of the greatest defenses of all-time.