Belichick Knows Game Theory

Occasionally during press conferences, Coach Belichick drops a pearl of wisdom. A few weeks ago, on September 17th, he gave a master class on game theory in response to an innocuous question. The question: what are the benefits of pre-snap motion? 

In football, on offense, you can have one player in motion at a time (as long as they’re not moving towards the line of scrimmage). Recently, pre-snap motion is being used more often across the NFL.

Something I have heard Coach Belichick say, that has worked its way into my notebook, is how he tries to gain an advantage with every play call. This applies to offense and defense, and is the complete opposite of calling plays just to call plays. It’s an important concept not just in football but in life regarding every action we take. 

Getting back to the football aspect, here’s how Belichick summarized his thoughts on using motion. Anytime you put a guy in motion, and with each and every play-call, you want to try to gain an advantage. Any time you don’t put guys in motion you’re also gaining certain advantages. What are you trying to gain? To gain an advantage in alignment to crack block or block a secondary support player? To get a player on the move? It could also be for some level of deception or forcing a defensive adjustment. 

However, the downside is you start to declare something about your formation and that eliminates certain things. You also don’t know exactly how the defense will react. They might have more than one way to adjust to it. So there are times where you want to be in a stationary formation and force a defense to declare, and there are other situations where you could gain an advantage with some movement on the play or in terms of eliminating some things that they’re not going to do. It comes down to how you feel about your game plan, matchup, and general thought process.

There are certainly some cases, like with Peyton Manning and the Colts, where the offense would stay in the same formation every time. So, the subtlest change by a defensive player’s alignment could tip off what they were doing. The decision comes down to gaining an advantage and whether it’s worth what you’re giving up by doing one or the other. Then Belichick actually apologizes for the long answer! I could’ve listened to this all day.

You could rip this description straight out of a game theory textbook on Nash equilibrium, or an economics textbook on opportunity cost. These are concepts that coaches in any sport should constantly be thinking about.