A little more on stopping the run as a means of generating turnovers

I brought up Manny Diaz’ philosophy last week and a couple of bloggers of a more statistical bent than I explored the topic as well.

At Football Study Hall, Chad Peltier did a little regression analysis on the subject and found that Diaz wasn’t full of shit.

There’s enough evidence to reject the null hypothesis that there isn’t a relationship between defensive rushing S&P+ and turnovers gained. Rush defense doesn’t explain the whole variation in the data on turnovers gained (r squared is .14), but the two variables do seem to be related in a non-random way (at the 95% confidence level).

In short, the stats do seem to support Diaz’s argument that a defense should work on stopping the run first and foremost for more turnovers.

And today at Team Speed Kills, David Wunderlich does a little statistical exploration, finds some correlation, but wonders if there’s more to it than what Diaz suggests.

But wait a second. Let’s apply a different truism, this one from Football Outsiders: “You run when you win, not win when you run.” As Aaron Schatz explained it:

There are exceptions, usually when the opponent is strong in every area except run defense… [h]owever, in general, winning teams have a lot of carries because their running backs are running out the clock at the end of wins, not because they are running wild early in games.

Apply this to a defensive context, and winning teams will defend more passes than runs. Certainly it’s possible to have a great defense that doesn’t win a lot of games—see Auburn and Tennessee in 2008, or Florida in 2013—and it’s possible to win a lot of games with a terrible defense—see 2011 Baylor, which won 10 games despite being 113th in scoring defense. There are always exceptions, and that’s why these correlations are in the +/- 0.300 to 0.400 range rather than, say, the +/- 0.700 to 0.800 range.

Still, teams that win a lot of games usually have good defenses. We should also expect that good defenses will force a lot of turnovers. We’re now stuck in the correlation vs. causation trap. Does strength at stopping the run cause a team to generate more turnovers? Or does simply being a good defense cause that unit to both stop the run and generate more turnovers?

I’ve always believed that context matters, so I would be stupid to dismiss David’s qualifiers there.  But it’s worth mentioning that Louisiana Tech, while leading the nation in turnovers last season, finished 9-5.  Take that for what it’s worth.

In the meantime, let’s see what Diaz does in his second tour of duty at Mississippi State.  As David concludes,

One thing I can say for sure is this: when you share a division with Nick Saban, Bret Bielema, Gus Malzahn, and Les Miles, focusing on stopping the run isn’t a bad plan.


Filed under Stats Geek!, Strategery And Mechanics

10 responses to “A little more on stopping the run as a means of generating turnovers

  1. JCDAWG83

    It seems simple to me. If you stop the run, the other team has to throw. When the ball is thrown, three things can happen and two of them are bad.


    • 69Dawg

      Nail on head.


      • Uglydawg

        When you run the ball only three things can happen
        1. stopped for no gain or loss (= to incomplete pass or qb sack)
        2. Gain (= completed pass)
        3. Fumble (= interception)
        Statistics tell a story, but not completely. If you have such a terrible offense that it goes three and out every possession, you are going to be playing defense most of the time. The only way to get a positve turnover is on defense or special teams. Offenses can only give negative turnovers.
        If your playing defense 80% of a game, you ought to get a few more turnovers….even if your team never wins a game.
        But yeah..stop the run first…I do agree with that because when a QB hands a back the ball..he’ll score everytime if he’s untouched.


        • pete

          “Statistics tell a story, but not completely.”

          That’s right Ug. Remember what CMR said when asked about controlling the time-of-position. He said. “That’s great…if your scoring”.

          We always say you have to run the ball! Or more correctly, you have to run the ball successfully! If your opponent is stuffing your run, then how many 3-n-outs do you go before trying a pass? That being said, I do believe there are more opportunities for error once a ball is in the air. I believe it starts with running the ball successfully on O (thus becoming a threat demanding help in the box) and stopping the run on D (thus forcing a team to become more one dimensional and predictable). But you can’t sell out on something that is not working for you. If we are against a team that is built to stop the run and applies most of its effort to doing so…then you better be able to take advantage down field.


          • Uglydawg

            Agreed, pete. Woody Hayes is most famous for the “When you pass” quote. He was a pretty good coach, if I remember correctly.


  2. Dawg in Austin

    La Tech may have been 9-5, but they were coming off a 4-8 season and went up against a tougher schedule. Having a better quality of defender ought to help Diaz against that competition this year, now that MSU has recruited better since his last stint.


  3. The stop the run first seems simple but it really depends upon the quality of the opposing teams passing game. Grantham got a bunch of shit for letting lattimore get some ungodly amount of yards on 37 carries in Columbia in 2010 but in doing so he kept the game within reach. Had we sold out to stop lattimore spurrier would have ran the scoreboard up and we’d have never made a game of it. All things being equal and you don’t have 9 of the best players on the field when playing defense you should focus on stopping what the other team wants to do. So against tech you have to take that dive away. Against auburn you have to take the outside runs away. Take the other team out of its comfort zone. This is why balance is so important. If you do both well, the defense can’t stop everything. If it tries to take one thing away you are capable of doing the other.


    • Uglydawg

      +1 Seems obvious, but sometimes it’s hard to know what a team that does both well is going to do. The answer..both…with a heavy measure of the one that is perculating the best. This is known as good offfensive balance and is very hard to defend/beat.
      Hoping the Dawgs have both.


  4. This coorelation not causation,IMHO


  5. Mayor

    So, lemme get this straight. Hard-hitting, aggressive defensive play against the run DOES cause fumbles and ultimately turnovers, after all? Gee, and previously we had been led to believe it was all luck. 🙂