The Advanced Stat of the Week this week is Passer Rating Differential.
Passer rating has scores of critics. The most common complaints are that it overvalues completion percentage, it has no opponent adjustment, it has no way of adjusting for game situation, it doesn't value running at all, it doesn't account for sacks or fumbles, it is ridiculously hard to calculate and it was scaled in the 1970s, making it notoriously useless for comparing quarterbacks of different eras.
Other than that, it's great!
Actually, I have always had a soft spot in my heart for passer rating. Aside from the fact that it correlates well with winning, it always seemed like the stat that Joe Montana led the league in, and that has to count for something, right?
I realize that I'm being uncharacteristically kindhearted to the deeply flawed and possibly useless number, but passer rating is here to stay and is still infinitely more useful than ranking teams and players by yards. Passer rating is so painfully mainstream that addressing it as an "advanced stat" would make a mockery of the holy name of advanced stats.
So, this week I'm going to tip my hat to our dear, lame old friend and address Passer Rating Differential.
Passer Rating Differential (PRD) essentially compares offensive and defensive passer ratings. One of the reasons I enjoy it so much is that the top eight teams in PRD all made the playoffs in 2011. It covers the gamut of teams from the Packers and Saints (great offensive passer ratings, mediocre defensive ones) to the Ravens and 49ers, who posted outstanding defensive numbers.
PRD shows us that it doesn't matter what combination you use to get the job done. Stopping the pass and passing the ball is the key to winning in the NFL.
Rounding out the week is the Houston Texans. Houston had a breakthrough 2012 season, and PRD indicates that it was thanks to great play on both sides of the ball. The Texans were third in the NFL with a PRD of 23.7. They fared well on both sides of the ball, finishing second in defensive passer rating and seventh in offensive passer rating.
It's little surprise that the Texans were considered a Super Bowl favorite for much of the season. A season like 2011 means there's a lot to be excited about when it comes to the Texans. There is still a little room for improvement offensively, as Matt Schaub's passer rating of 96.8 was higher than the final team number. The Texans were brought down some by the play of T.J. Yates (80.7).
A full season by Matt Schaub at quarterback should be worth an extra few points, as he's posted a rating of at least 92.0 in each of the last four seasons.
The question whether the Texans can sustain their defensive performance. I believe they are primed for some measure of regression. In just one year, they went from dead last in defensive passer rating to second. While there were good reasons for that jump (Wade Phillips, Johnathan Joseph, Danieal Manning), that kind of increase is bound to have a bit of a yo-yo effect in year two.
This is by no means unprecedented. If you look at the top five teams in PRD in 2010, three of them regressed in 2011, and two of them regressed significantly. This is a fairly common occurrence.
I consider it likely that the Texans' pass defense regresses at least somewhat in 2012. Fans don't like the "power of gravity" when it comes to stats, but regression is a reality. Big swings tend not to be sustainable all at once.
The good news is that even if the Texans' defense regresses as much as ten points in defensive passer rating, they would still have a top-10 pass defense. Coupled with a full year from Matt Schaub, and the Texans should still be looking at a top-five PRD and a playoff spot.
If they buck the trend and have another top year defensively, they will likely earn a first-round bye and be primed for a deep playoff run.