If you like using points per game as a reference for team strength (SOS), it makes sense to adjust for strength of opponent. Pro Football Reference has been doing this for years with their Simple Ranking System; in fact, the term “SRS” is now commonly used to refer to a team’s point differential that has been adjusted for SOS. PFR goes even further by giving us offensive and defensive ratings – OSRS and DSRS – which are pretty handy for seeing where a team’s strength comes from (or how balanced a team is, etc.).
But being the nitpicker that I am, I can’t help but point out that PFR’s OSRS isn’t a “true” reflection of a team’s offensive strength because it includes points not scored by the “offense proper”, namely, pick-sixes, fumble return touchdowns, kickoff/punt return touchdowns and safeties (I consider the extra-point part of the offense, although perhaps that should be looked at). And the same goes with DSRS – it includes points that weren’t really allowed by the defense.
To remedy this insufferable situation, I take the time to remove those pesky “non-offense” scores, and then run the adjustment. In most cases, these scores don’t matter because they’re rare, but in some cases they do: the Bengals have scored 28 such points, which amounts to about a field goal per game.
Below are the SRS numbers through Week 8. To differentiate “my” offensive/defensive ratings from PFR’s, I use the terms OffPF SRS and DefPA SRS. “SpD” (special teams/defense) is not a special teams rating, it’s just the points left over after we subtract the “pure” offensive and defensive SRS ratings from the total SRS rating.
No surprises here as far as which teams are “good” and “bad”, but some interesting nuggets when we look at offenses and defenses. Two things jump out me at looking at Off PF SRS: the Steelers are below average, and the Colts are surprisingly good. Defensively, I’m surprised to see the Ravens at #8 considering they’re ranked #2 in points allowed (defense only of course), and it’s a damn good thing the Chiefs offense is great because their defense is a real liability.
I’ll be posting these numbers every week, probably with not near as much commentary. Thanks all.