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On Vick, Foles, and Momentum in the NFL

If momentum exists in the NFL (some say, convincingly, it doesn't), then should Chip Kelly start Nick Foles against the Dallas Cowboys?

Al Messerschmidt

Back in August, Bill Barnwell wrote two great articles examining the existence of momentum in the NFL (Part I, Part II). His conclusion: it doesn’t really exist, and this "nomentum" doesn’t have any impact on outcomes in the NFL. He attacked the concept statistically and logically, yet much like I did with Brent Cohen’s argument for luck (or , fumble luck), I found myself playing the contrarian. How can something so pervasive as momentum, so ingrained in sports culture, not be applicable? Well, I think it is, and I think it can be applied to the Philadelphia Eagles’ current quarterback situation.

One of the ways Barnwell disproved momentum statistically is by using Pro-Football-Reference’s Drive Finder. From 1999 to 2012, he looked at results of drives that started within a team’s own five-yard line that began under three separate circumstances: by receiving a punt, by stopping the opposing team on downs, or by creating a turnover. He hypothesized that, if momentum exists, teams that gained the ball as a result of stopping the opposing offense on downs would score more points. The Drive Finder results showed that teams actually scored the least amount of points when drives began after stopping the opposing offense on downs.

Means of Possession Drives Points per Drive
Punt by opposition 1,154 0.95
Stopped opposing offense on downs 105 0.91
Takeaway from opposing offense 217 1.21

But momentum is extremely circumstantial and I’m not sure if Barnwell’s definition (starting a drive within a team’s own five-yard line) is circumstantially best. Instead, let’s look at a more defined situation. If we look at teams who are at least a touchdown behind in the fourth quarter and start their drives as a result of punts, turnovers, or downs, we see quite different results.

Means of Possession Drives Points per Drive
Punt by opposition 1,790 1.69
Turnover/Downs 373 2.68

Teams that start their drive as a result of turnovers and downs when behind in the fourth quarter, presumably when emotions run higher and "momentum" is more substantive, score on average one more point than teams that start their drive as a result of a punt. Quantitatively, these two situations are very similar: drives that start with punts average 5.9 plays, 2:09, and 31.9 yards per drive; drives that start with turnovers/downs average 5.1 plays, 2:02, and 25 yards per drive. The biggest significant difference is points. And, by the way, this phenomenon is equal for away teams and home teams, possibly showing how this concept of momentum overrides any advantage posed by the home field, which exists.

Admittedly, there may be some correlation/causation things going on here, but for the sake of argument, let’s say this illustrates, on a small scale, momentum. I say "on a small scale" because momentum exists on different levels. Barnwell acknowledges this in his logical argument, "Momentum scales to fit any argument you possibly want to make over an indeterminate amount of time". Well of course it does. Momentum does not exist on a single plane. It’s on every plane of existence imaginable. There are instances of momentum within other instances of momentum within others. All of which have an impact on each other, all of which impact events locally and globally. All of which, I think, are real.

If we can illustrate that momentum exists on a small scale, let’s turn our attention to the Philadelphia Eagles and apply it to a larger one. Michael Vick won the starting quarterback battle in the preseason then lost it due to injury. In turn, Nick Foles looked impressive in a victory against a tough Tampa Bay defense. If healthy, should Vick regain his role and start against the Dallas Cowboys? If momentum truly exists, I think not. There have been payoffs in such situations (see 2010 Philadelphia Eagles, 2012 San Francisco 49ers).

*Sidenote: I also think Chip Kelly has a soft spot for Foles, due largely in part to this play against his Oregon team:

The thing is, just as momentum can be built, there are opposing forces that exist to stop it. Those forces can take the form of an opposing defense, or it can take the form of a coach’s decision, poor, fortuitous, or otherwise. So, in my opinion, if there is such a thing as momentum, it makes more sense for Chip Kelly to ride the wave and start Nick Foles, hypotheticals be damned!

But more than momentum can potentially indicate, it just "seems" rational, doesn’t it?