Wednesday, February 11, 2009

Season in Review: Points Allowed (2008)

We began our review of the 2008 season with a look at the points scored by the Steelers' offense (the short version: not many). We now shift our focus to the defense, and if any of you are surprised by what we found then you just were not paying attention this season.

The 2008 edition of the Steelers' defense grudgingly gave up 223 points ~ the second lowest total for a Pittsburgh defense in the past nine seasons (inclusive ~ the 2001 defense gave up 212 points, and that year the Steelers went 13-3), and the third lowest total by a Super Bowl champion during that same period (the 2000 Baltimore Ravens gave up 165 points, and the 2002 Tampa Bay Buccaneers surrendered 196).

Interestingly the 2008 defense compares more favorably then the 2001 Steelers' defense when compared to the league average (i.e. the average points given up by defenses around the league). Here is a chart that highlights that fact:

The blue line represents the average NFL scoring defense for each season, the pink line represents the points allowed by the Steelers, and the yellow line represents the variance between the two. Since being just better than average in 2006 the scoring defense has improved in both of two most recent seasons. Indeed, it has improved to the point that the Steelers have now surrendered the fewest points over the past nine seasons. Here is a look at the top five scoring defenses, 2000-2008:

TeamPoints Allowed
Tampa Bay2,533
New England2,612

The only surprise here is how well Tampa Bay ranks, and it is testimony to how choosing a sample set can have a profound impact on the results. In three of the past five seasons the Bucs have surrendered 300 or more points (including 323 this past season), however in the four prior seasons (i.e. 2000-2003) they never surrendered more than 280 points in any one season. We do not want to say that anyone was living off their reputation but it seems clear that Tampa Bay's defense has seen better days.

As for the Steelers it is difficult to imagine that they could improve on their 2008 performance; however the 2001 group has set the bar (i.e. in terms of scoring defense) and until they surpass that group then improvement remains possible.