The most persistently wrong thing I was wrong about amongst the many persistently wrong things I asserted about Rich Rodriguez and his bite-sized Era at Michigan was: "that turnover margin is going to be a lot closer to zero this year." Or words to that effect.
I should have been right, or at least in the general ballpark of right. Rodriguez's West Virginia teams were consistently in the black. Turnover margin is so weakly correlated from year to year that Phil Steele annually puts out a "turnovers = turnaround" post highlighting teams with double-digit swings in either direction so that he can predict against the teams with big numbers and in favor of the teams with little tiny ones. Here's your favorite team:
And here's how that worked out:
Amongst the many things that got Rodriguez fired, the persistently huge negative turnover margin is neck and neck with transferpalooza and program alum white blood cells for second place.
So these days, running across stats like these…
running the correlation between one year's turnover margin and the next, I found that the correlation was a mere 12%. That's still something, but it's clear that for most teams, the turnover margin they enjoy one year has virtually zero predictive value for the turnover margin they will enjoy the next year. That means that on average, teams with substantially positive margins will see major decline in margin the next year, and teams with substantially negative margins will see major improvement the next year. A team with a -10 turnover margin in 2009, for example, would have an expected turnover margin of -1.2 in 2010, an improvement of nearly a full turnover per game!
…make me want to bang my head against the wall. Of course Michigan would be as large of a chunk of that correlation as possible, and of course they would be on the negative side of things. Thump. Thump. (The only thing worse than defying this correlation is defying the correlation between turnovers and wins: GTP points out Georgia went from –16 to +10 and still finished two games worse than they did last year. That would seriously harsh my buzz if I was a Georgia fan.)
I have tried to make the world make sense and this is what I've come up with:
- The correlation is so low because quarterbacks are so important. The general path of a quarterback is: bench, horrible interception-laden youth, cool as a elderly cucumber, repeat. When you have a senior quarterback you are likely to have a good turnover margin and guaranteed to not have that guy back next year.
- The same goes for everywhere else, albeit to a lesser extent. Good defenses tend to have seniors on them and tend to not have many returning starters.
- Michigan eschewed the general path in favor of freshmen or equivalents. Rodriguez never started the same guy two years in a row, and while that turned out to be the right decision it meant three straight years of horrible interception-laden etc.
- When your defense is so, so bad you escape TO margin gravity. AKA GERG. Also, what's the one thing that consistently generates turnovers? QB pressure. Michigan finished 98th in sacks and loved them some three-man rushes.
So while year-to-year correlation is low across college football, if you correct for experience—especially at QB—and maybe lack of prominent walk-ons/converted WRs in the secondary that 12% would be significantly larger. Michigan's program got so messed up that they stopped participating in the circle of turnovers*. Instead they laid at the bottom of the national rankings, a corpse dragged down by redzone interceptions.
Seriously, This Time It's Serious
Um… so… there's the above theory. And then there's Denard Robinson, Michigan's first returning starter at QB since Chad Henne. And then there's Greg Mattison and a defense that uses Craig Roh as a pass rusher instead of a clunky linebacker. There are a bunch of returning starters everywhere, including four guys on the offensive line.
I'm going to be the guy who puts his hat on a stick and pokes it out of a trench to see if there are any snipers around, again: Michigan's turnover margin should scream towards zero this year. They've got gravity on their side and many things besides. Also, Brady Hoke's miraculous digestive tract will move all that Tyler Sash wackiness to Ann Arbor.
This is the year Michigan has a mediocre turnover margin. Believe.