Wednesday, October 3, 2012

The Turnover Index - Week 5

One of my first posts on this blog was on the topic of NFL Turnover Differential and the Point Spread. In that post, I found that teams with fewer season-to-date defensive turnovers than their opponent tended to cover the spread more often than not.  The presumed reason for this is that:

  1. Turnovers are more random than the betting public realizes, and so the point spread "overcorrects" for prior game turnover performance.
  2. To the extent that turnovers are not random, they are more a function of the offense.  Interceptions are more "thrown" than caught and fumbles are more "lost" than forced.

From 1998-2011, when a team has at least 10 fewer defensive turnovers than its opponent (going into the game), it covered the spread 59% of the time.  This phenomenon was fairly consistent year over year (in 2011, the spread was covered 70% of the time in the 20 games in which this occurred).

As promised in the orignal post, I'm going to see if this phenomenon holds for the 2012 season.  This will be a weekly feature in which I'll highlight any upcoming games that meet the turnover differential criterion.

Here are the Week 5 match-ups and turnover differentials:

"home.dto" specifies the defensive turnovers season-to-date for the home team and "away.dto" are the same for the away team.

One game this week qualifies under our criterion: Chicago at Jacksonville.  Chicago's defense has produced 14 turnovers this season, and Jacksonville's has only produced 4, with a differential of 10.  So, one would predict that Jacksonville is more likely than not to cover the point spread in their matchup against Chicago.

I'll keep a running tally throughout the season on how well this approach does against the spread.  If the advantage disappears I will be forced to conclude that this blog is so wide-read and influential that the lines have recallibrated to reflect my analysis (and that each and every one of my readers is a billionaire compulsive gambler).

7 comments:

  1. The JAX/CHI line has shrunken to 4.5. If this turns to be a pattern, the public may have caught on just now. I know, the odds of that happening...

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  2. Interesting. It now appears to be back up at 6 points.

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  3. Ouch. Just one game, no biggie. :)

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  4. Any chance of updating for week 6? Thanks!

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  5. Should be up either today or tomorrow. I can give you the bottom line: Oakland to cover against Atlanta (the only matchup with at least a 10 turnover differential between the teams).

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