Greatest Scoring Defenses
|Scoring has reached an all-time high this season|
My assumption when I started the research was that there would be a gradual rise in scoring throughout NFL history. Not so. The 60s had their share of points, but offenses went to pot in the 70s. ColdHardFootballFacts.com calls this the “dead ball” era of the NFL. Things picked up in the 80s with the advent of the West Coast Offense, but stayed relatively flat until a couple years ago. There are plenty of guesses to be made about why scoring has picked up recently, but for our purposes, the only thing that matters is that scoring is going way up.
That matters because just taking a snap shot of the defenses who have help opponents to the lowest totals in history tells a tainted story.
Note that six of the top ten scoring defenses played in the 70s. To factor in the context for what types of offenses these defenses faced, I calculated the standard deviation for scoring in each season. Having that number allows us to see just how exceptional a defense was relative to the amount of scoring that was going on that year.
16 of the top 30 scoring defenses in history made it to the championship game (even before it was the Super Bowl), with 12 coming away victorious
No team has ever allowed fewer points per game than the Seahawks current 14.6 in a season when the average league scoring was 22.5 or greater.
Greatest Pass Defenses
The Seahawks Legion of Boom gets plenty of publicity, and deservedly so. Each starter has either made the Pro Bowl or All-Pro team, and the three corners that come in as substitutions have proven themselves worthy of starting roles. There are plenty of advanced stat gurus that dismiss the classic passer rating as a flawed statistic. It does not take into account situation, rushing yards or sacks. The QBR stat that has become popular lately, does not go back far enough to be useful for this exercise, so passer rating will have to do.
Seattle would have finished 44th on this list in 2012, as they were -1.52 deviations below the norm. Decent, but not great. This season’s defense has made a sizable climb in the ranks at -1.70 deviations below the norm. That puts them just outside the top 30 at #32. Still not elite, but when added to the scoring numbers, it becomes clear that mentioning them with some of the all-time greats is not absurd.
The 2013 pass defense would rank far higher if not for what is the largest standard deviation (11.5) of any season in the NFL. The difference between the best passing teams and the worst passing teams has never been greater, and that makes it harder to separate yourself from the pack. If the deviation was the same 7.9 it was last season, this Seahawks unit would rate as one of the five best pass defenses in history.