Houston Texans Advanced Stat of the Week: Regression Kills on Defense

Nate Dunlevy@NateDunlevyGuest ColumnistFebruary 11, 2013

Joseph's struggles hurt the Texans defense.
Joseph's struggles hurt the Texans defense.Thomas Campbell-USA TODAY Sports

Even the best NFL teams have a hard time moving forward every single year.

The Houston Texans are no exception. They saw their rankings in a key statistical indicator decline in 2012.

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.

The problem for Houston in 2012 is that as the season wore on, they weren't as good at either as they were early in the year.

After the 2011 breakthrough campaign, I made the argument that Houston would have a hard time improving over their outstanding ranking in the stat. They weren't likely to advanced on either side of the ball.

Regression happens.

Offensively, the Texans had a slight decline from 2011, even without T.J. Yates getting significant time. Matt Schaub simply wasn't as effective in 2012 as he was in 2011. His YPA dropped by a full yard, pulling down his his passer rating by more than six points.

Defensively, the Texans went backwards as well. They had one of the league's top pass defenses in 2011 and were good, but not great, in 2012.

Before Schaub was lost for the season late in 2011, the Texans looked like a potential Super Bowl team and were arguably the best team in football. Their PRD was at an all-time high. The same thing was true halfway through 2012.

The difference between Schaub in the first and second half of the season is well documented, as is the collapse of the Texans defense.

PRD isn't a perfect stat, but it nicely captures the essence of a good, but not great Texans team that fell off from 2011.