This week at the New York Times, I look at the dominant Seattle pass defense.
As the passing revolution overtakes the N.F.L., football fans have become immune to the avalanche of falling records. Teams are averaging 239 passing yards per game and completing 61.3 percent of passes, metrics that would be single-season records. Peyton Manning is on a pace to break the single-season record for passing yards and passing touchdowns, and there was discussion last week that he was not even the most valuable player in the league. Josh Gordon set records for receiving yards in a two-, three- and four-game stretch this season, and the Cleveland Browns lost each of those games. You can forgive fans for not being impressed by gaudy passing numbers when Philadelphia Eagles quarterback Nick Foles starts the season with 19 touchdowns and no interceptions.
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The league average Adjusted Net Yards per Attempt this season is 5.97, which would also be an N.F.L. record. (The previous high was 5.93, set last season.) The Seahawks have allowed just 3.40 ANY/A, easily the best in the league (San Francisco and Carolina are second and third at 4.62 and 4.73). But since the ANY/A league average has been rising for years, we cannot just compare Seattle to teams of yesteryear. We also need to measure how far from the league average each pass defense has performed.
The simplest way to measure deviation from the average is to measure the standard deviation among all pass defenses in the N.F.L. In 2013, the standard deviation of the ANY/A ratings of the 32 teams is 0.93. As a result, Seattle’s pass defense is 2.76 standard deviations above the 2013 mean of 5.97. If the Seahawks can maintain that level of dominance, it will rank as the fourth best season since 1970.
By this method, the top pass defense was fielded by Tampa Bay in 2002, the year the Buccaneers won the Super Bowl. In 2002, Tampa Bay allowed 2.34 Adjusted Net Yards per Attempt; that season, the league average was 5.35 and the standard deviation was again 0.93. As a result, the Tampa Bay pass defense was 3.22 standard deviations better than average. In the postseason, the Buccaneers allowed just three touchdowns while scoring four touchdowns on interception returns.
You can read the full article here. Below are the top 75 pass defenses from 1950 to 2012 using this formula:
| Year | Team | ANY/A | LGAVG | STDEV | value |
|---|---|---|---|---|---|
| 2002 | Tampa Bay Buccaneers | 2.34 | 5.35 | 0.93 | 3.22 |
| 1988 | Minnesota Vikings | 2.15 | 5.02 | 0.89 | 3.21 |
| 1970 | Minnesota Vikings | 0.72 | 4.16 | 1.18 | 2.91 |
| 1982 | Miami Dolphins | 1.22 | 4.76 | 1.33 | 2.66 |
| 1985 | Chicago Bears | 2.74 | 4.86 | 0.9 | 2.37 |
| 1974 | Pittsburgh Steelers | 1.59 | 3.91 | 0.98 | 2.36 |
| 2008 | Pittsburgh Steelers | 3.17 | 5.7 | 1.09 | 2.33 |
| 1977 | Atlanta Falcons | 1.09 | 3.55 | 1.06 | 2.32 |
| 1980 | Washington Redskins | 2.36 | 4.87 | 1.08 | 2.32 |
| 2005 | Chicago Bears | 3.37 | 5.34 | 0.86 | 2.28 |
| 1998 | Miami Dolphins | 3.57 | 5.31 | 0.76 | 2.28 |
| 1965 | San Diego Chargers | 2.44 | 3.92 | 0.66 | 2.26 |
| 1969 | Minnesota Vikings | 0.96 | 4.67 | 1.65 | 2.24 |
| 1973 | Pittsburgh Steelers | 0.58 | 3.89 | 1.48 | 2.23 |
| 1987 | San Francisco 49ers | 3.21 | 5.04 | 0.83 | 2.19 |
| 1965 | Green Bay Packers | 2.31 | 5.01 | 1.24 | 2.19 |
| 2003 | New England Patriots | 3.26 | 5.2 | 0.89 | 2.18 |
| 1963 | Chicago Bears | 0.81 | 4.87 | 1.87 | 2.18 |
| 1986 | Chicago Bears | 2.63 | 4.96 | 1.07 | 2.17 |
| 1952 | Los Angeles Rams | 1.31 | 3.12 | 0.86 | 2.1 |
| 2006 | Baltimore Ravens | 3.64 | 5.38 | 0.83 | 2.1 |
| 1997 | San Francisco 49ers | 3.52 | 5.16 | 0.78 | 2.1 |
| 1962 | Green Bay Packers | 1.39 | 5.01 | 1.74 | 2.08 |
| 2010 | Green Bay Packers | 4.09 | 5.73 | 0.79 | 2.08 |
| 2001 | Cleveland Browns | 3.3 | 5.19 | 0.91 | 2.08 |
| 1961 | San Diego Chargers | 0.91 | 3.85 | 1.43 | 2.06 |
| 1994 | Dallas Cowboys | 3.76 | 5.38 | 0.78 | 2.06 |
| 1956 | Chicago Cardinals | 0.65 | 3.88 | 1.57 | 2.05 |
| 1991 | Philadelphia Eagles | 2.99 | 5.18 | 1.07 | 2.05 |
| 2004 | Buffalo Bills | 3.66 | 5.63 | 0.96 | 2.04 |
| 2009 | New York Jets | 3.48 | 5.65 | 1.06 | 2.04 |
| 2007 | Indianapolis Colts | 3.98 | 5.52 | 0.76 | 2.03 |
| 1969 | Kansas City Chiefs | 1.76 | 4.23 | 1.23 | 2.02 |
| 1990 | Pittsburgh Steelers | 3.24 | 5.29 | 1.02 | 2.01 |
| 1950 | Cleveland Browns | 0.49 | 3.15 | 1.33 | 1.99 |
| 1991 | New Orleans Saints | 3.06 | 5.18 | 1.07 | 1.99 |
| 1971 | Baltimore Colts | 1.67 | 3.93 | 1.15 | 1.96 |
| 1996 | Green Bay Packers | 3.12 | 5.14 | 1.03 | 1.96 |
| 2009 | Buffalo Bills | 3.57 | 5.65 | 1.06 | 1.95 |
| 1995 | San Francisco 49ers | 3.91 | 5.41 | 0.77 | 1.95 |
| 1964 | Washington Redskins | 2.31 | 4.6 | 1.18 | 1.95 |
| 2012 | Chicago Bears | 4.3 | 5.93 | 0.84 | 1.94 |
| 1997 | Green Bay Packers | 3.65 | 5.16 | 0.78 | 1.93 |
| 1967 | Green Bay Packers | 1.28 | 4.32 | 1.6 | 1.9 |
| 2008 | Baltimore Ravens | 3.64 | 5.7 | 1.09 | 1.9 |
| 2000 | Miami Dolphins | 3.29 | 5.21 | 1.02 | 1.88 |
| 1999 | Tampa Bay Buccaneers | 3.49 | 5.18 | 0.9 | 1.88 |
| 1986 | San Francisco 49ers | 2.95 | 4.96 | 1.07 | 1.87 |
| 1960 | Buffalo Bills | 2.2 | 4.06 | 1 | 1.86 |
| 1975 | Oakland Raiders | 1.21 | 4.04 | 1.52 | 1.86 |