I'm thinking about this Seahawks defense and wondering just how good they are, historically-speaking. It's gotta be more than a one-year sample (though there's nothing wrong with having a one-year, all-time great defense). Over the past three seasons, here's what the Seahawks' defense has done:
Seattle Seahawks, 2012-2014
- NFL rank in points allowed: #1, #1, #1
- NFL rank in yards allowed: #4, #1, #1
- Points allowed: 15.3, 14.4, 15.9
- Average NFL team per-game scoring: 22.8, 23.4, 22.5
- Points allowed +/- relative to NFL average: -7.5, -9.0, -6.6
- Yards allowed: 306.2, 273.6, 267.1
- Average NFL team per-game yardage: 347.2, 348.5, 347.5
- Yards allowed +/- relative to NFL average: -41.0, -74.9, -80.4
Those are some pretty incredible numbers. Let's compare them to some other all-time great defenses.
Chicago Bears, 1984-1986
- NFL rank in points allowed: #3, #1, #1
- NFL rank in yards allowed: #1, #1, #1
- Points allowed: 15.5, 12.4, 11.7
- Average NFL team per-game scoring: 21.2, 21.5, 20.5
- Points allowed +/- relative to NFL average: -5.7, -9.1, -8.8
- Yards allowed: 241.4, 258.4, 258.1
- Average NFL team per-game yardage: 329.8, 329.4, 324.2
- Yards allowed +/- relative to NFL average: -88.4, -71.0, -66.1
Baltimore Ravens, 1999-2001
- NFL rank in points allowed: #6, #1, #4
- NFL rank in yards allowed: #2, #2, #2
- Points allowed: 17.3, 10.3, 16.6
- Average NFL team per-game scoring: 20.8, 20.7, 20.2
- Points allowed +/- relative to NFL average: -3.5, -10.4, -3.6
- Yards allowed: 263.9, 247.9, 277.9
- Average NFL team per-game yardage: 318.8, 319.4, 317.6
- Yards allowed +/- relative to NFL average: -54.9, -71.5, -39.7
Pittsburgh Steelers, 1974-1976
- NFL rank in points allowed: #2, #2, #1
- NFL rank in yards allowed: #1, #4, #1
- Points allowed: 13.5, 11.6, 9.9
- Average NFL team per-game scoring: 18.2, 20.6, 19.2
- Points allowed +/- relative to NFL average: -4.7, -9.0, -9.3
- Yards allowed: 219.6, 261.5, 237.4
- Average NFL team per-game yardage: 286.5, 308.3, 302.7
- Yards allowed +/- relative to NFL average: -66.9, -46.8, -65.3
Miami Dolphins, 1971-1973
- NFL rank in points allowed: #3, #1, #1
- NFL rank in yards allowed: #5, #1, #3
- Points allowed: 12.4, 12.4, 12.2
- Average NFL team per-game scoring: 19.4, 20.3, 19.5
- Points allowed +/- relative to NFL average: -7.0, -7.9, -7.3
- Yards allowed: 261.5, 235.5, 234.4
- Average NFL team per-game yardage: 285.8, 291.4, 285.3
- Yards allowed +/- relative to NFL average: -24.3, -55.9, -50.9
Minnesota Vikings, 1969-1971
- NFL rank in points allowed: #1, #1, #2
- NFL rank in yards allowed: #3, #4, #4
- Points allowed: 9.5, 10.2, 9.9
- Average NFL team per-game scoring: 20.9, 19.3, 19.4
- Points allowed +/- relative to NFL average: -11.4, -9.1, -9.5
- Yards allowed: 194.3, 200.2, 243.3
- Average NFL team per-game yardage: 299.4, 281.8, 285.8
- Yards allowed +/- relative to NFL average: -105.1, -81.6, -42.5
It's a little hard to determine which of these units, over a three-year period, is the "best". Minnesota's defensive numbers, relative to league-average, are absurd. But those teams never won a Super Bowl, and they had the #1 and #3 scoring offenses in the NFL in 1969 and 1970, respectively. So they SHOULD have won a Super Bowl in there somewhere. They gave up 23 points to the Chiefs in SB4, then got beat 17-14 by the 49ers in the Divisional Round the next year, and then lost to Dallas 20-12 the following year in the Divisional Round. So in the big spots, their defense, which gave up 9.5, 10.2, and 9.9 points per game, allowed 23, 17, and 20, respectively, in their playoff losses. In other words, they were WORSE in the big game.
Pittsburgh's defenses were incredible all the way around. The Bears? Their 1986 playoff run was off the charts. In those three games, here's what they allowed:
Divisional Round vs. Giants: 0 points, 181 yds, 10 first downs
NFCCG vs. Rams: 0 points, 130 yards, 9 first downs
Super Bowl vs. Patriots: 10 points, 123 yards, 12 first downs (yay, NE played them the hardest!!!)
I mean, that's just ridiculous. 10 total points, 434 total yards allowed. IN THREE PLAYOFF GAMES!!!
Even Seattle's defense, as incredible as it's been the past three years, cannot come close to that. But I'd still say that Seattle's three-year run on D puts them right there with the greatest defensive units in the Super Bowl era (I confess I didn't look at the NFL in the 1940s or so).
They are going to be VERY tough to beat.