Refchat Index: Analyzing Strength of Schedule for the 2009 NFL Season

In our last blog posting, we explained that the visiting team's offense has a surprisingly smaller impact on the result of the game (both when you account for scoring margin and when you focus only on which team won) than either the visiting team's defense, the home team's defense, or the home team's offense.

We can use this to make an adjustment in predicting a game or analyzing which team has a tougher schedule. We'll make an adjustment that puts the most weight on the home team's offense, a good amount of weight on each team's defense, and a small weight on the visiting team's offense. Let's call this the Refchat Index.

Let's look at which teams have the strongest and weakest schedules in the 2009 NFL season based on how their opponents did in 2008. We'll focus first on the scoring margin for each team. Next, we'll roll out the Refchat Index and analyze the schedules using our weighted analysis.

Under raw scoring margin, the teams with the easiest schedules based on how the opponents fared in 2008 are: Green Bay Packers, Arizona Cardinals, Minnesota Vikings, Baltimore Ravens, and the Seattle Seahawks. The teams with the hardest schedules based on raw 2008 scoring margin are: Miami Dolphins, Carolina Panthers, Tampa Bay Bucs, Atlanta Falcons, and the New England Patriots.

But using the Refchat Index, the teams with the easiest 2009 NFL schedules using 2008 data are: Arizona Cardinals, Green Bay Packers, Pittsburgh Steelers, St. Louis Rams, and the Chicago Bears. The teams with the hardest schedules are: Carolina Panthers, Miami Dolphins, Atlanta Falcons, New England Patriots, and the Tampa Bay Bucs.

Comparing the Refchat Index to the raw scoring data, the teams whose schedules are much easier using the Refchat Index are: St. Louis Rams (4th easiest rather than 11th easiest), Pittsburgh Steelers (3rd easiest rather than 7th easiest), and the Washington Redskins (17th easiest rather than 21st easiest).

The teams whose schedules look much harder when you apply the Refchat Index are: Cincinnati Bengals (21st easiest rather than 14th easiest), Detroit Lions (18th rather than 13th), and the Baltimore Ravens (9th rather than 4th).

So if you use the rough yardstick of how opponents did in 2008, then the Refchat Index suggests that the Rams, Steelers, and Redskins may do better than most people predict (although the Redskins still have a tough schedule) and that the Bengals, Lions, and Ravens may do worse than most people predict (although the Ravens still have an easier than average schedule).

Of course, a big problem with this analysis is that NFL teams do not stay consistent from year to year, but if you want an overview of the upcoming season, this is how the Refchat Index would influence the analysis.