Game Theory in NFL Playcalling: Why Teams Don’t Pass 100% of the Time
In football, an offense has a choice between two options on any given play – run the ball or pass the ball to gain as many yards as you can. On average, passing the ball is expected to net you approximately 2.5 more yards than running the ball on any given play according to the wolfsports.com article. So, why don’t teams pass the ball more often? Well,If an offense passes 100% of the time, the defensive coordinator knows exactly what’s coming and can counter it. Likewise, if a team runs the ball 100% of the time, the defensive coordinator will be able to counter that. Therefore, there is no dominant strategy in this game where playing either run or pass 100% of the time will be effective at all.
Football is a game of unpredictability; becoming too predictable invites your opponent to counter your gameplan. So, we know why teams don’t pass the ball 100% of the time. However, applying game theory in football does not just make you unpredictable to your opponent; you can use it to tailor your own strategy to your own team strengths.
For example, a team with a great running back like Derrick Henry or Jonathan Taylor will run the ball more often, because the payoff for running is greater. This makes sense, as any casual NFL fan knows that giving Derrick Henry more opportunities to run the ball is beneficial to his offense. The expected payoff for a successful Derrick Henry run is higher, because the upside on any given run is that Derrick Henry breaks free and scores a touchdown. Whereas, with a mediocre running back like Devin Singletary who isn’t as gifted as Henry, the best-case scenario is approximately 20-30 yards instead of a touchdown.
Likewise, a team with a prolific quarterback and/or wide receivers would want to pass the ball more. The same logic of putting the ball into your best players’ hands applies – letting Patrick Mahomes throw the ball at a high rate is going to be more advantageous to your team than if you otherwise did not have as good a quarterback. This is because the expected payoff for a successful pass play is greater with a strong-armed, accurate quarterback, or a receiver who can make spectacular catches. When the defense stacks the box to stop the run and a receiver is able to get open downfield, having a quarterback who can consistently make downfield, big-time throws is essential. Inversely, take the Pittsburgh Steelers who have an inaccurate quarterback in Mitch Trubisky but a great running back in Najee Harris. The Steelers would not want to be a pass-heavy team. This is because although Mitch’s yards per pass attempt will be greater than Najee’s yards per rush attempt (Mitch has a career YPA of 6.7, while Najee Harris has a RPA of 3.9), the consistency (or lack thereof) at which Mitch will throw his receiver an accurate football caps the upside of the Steelers’ passing attack. Yet, Najee Harris has a high rate of successful runs and positive plays that keep the Steelers ahead of the chains.
Football is a game of constant action and reaction. An offense comes out with a gameplan, causing the defense to counter. Then, the offense re-adjusts to the defense, and so on. This is why in-season and in-game adjustments are paramount to success in the NFL. Good playcallers time their runs and passes with the flow of the game and understand what adjustments the defense is making. For example, say that the Steelers’ opponent is stacking the box to contain Najee Harris because their game plan is to stop the Steelers’ best offensive weapon. However, the Steelers have the option in-game to pivot to a more pass-heavy offense. Although Trubisky is a bad NFL quarterback, even he can have an efficient day if the defense spends too many resources committing to stop the run. Yet, once the pass game has success, the defense can stop stacking the box in order to prevent the pass, which again leaves running lanes open for Najee Harris.
Playcalling both on offense and defense is a balancing act; it is a game of strategies and payoffs that playcallers must decipher the Nash equilibrium for pre-game and in-game.
https://www.fieldgulls.com/seahawks-analysis/2015/1/9/7517551/understanding-effective-play-calling-with-game-theory