In the mid-19th century, the USS Central America would regularly sail between New York to Panama. This was the middle of the California Gold Rush, so the boat was often full of prospectors and their hauls. In 1857, the USS Central America sank somewhere off Charleston’s coast, dragging down over 500 passengers and over $100 million in gold.
Fast forward 130 years, when a treasure hunter named Tommy Thompson decided he wanted to find that loot. Finding a single shipwreck in the ocean is impossibly hard. By just guessing and checking, it would be about as likely as stumbling upon a single grain of sand in a four-bedroom floor plan. So Thompson needed to deploy some advanced math.
Bayes’ Theorem is a mathematical concept that helps determine how probabilities change when new information is introduced. When the NFL expanded the playoffs to 14 teams, for example, the probability that the No. 1 seed would win the conference increased. Bayes’ Theorem is the tool used to calculate the difference.
Thompson used Bayesian math to help streamline his search. Each patch of ocean that didn’t turn up bountiful treasure was also a piece of information. Given that the treasure wasn’t here, it changes the probability that it’s over there. Using Bayes’ Theorem, he could sort more quickly through the vast open sea and hone in on the USS Central America’s remains.
After just three summers of searching, despite bad weather, faulty equipment, and clashing egos, Tommy Thompson found the haul he was looking for.
Bayesian probability is a potent tool that can be applied to football as well. We can get a better understanding of target shares, quarterback decisions, and general play-calling. And Kirk Cousins is perfectly suited for such a study.
This won’t be an evaluation of Cousins. He is just a good example we can use to learn more about NFL progressions. Because Cousins is extremely consistent in how he reads plays, it’s easy to learn the basics through watching him play. Where other quarterbacks may leave the progression in certain scenarios, Cousins applies a very constant approach. That can be good or bad depending on the situation, but when trying to learn more about NFL play design, it makes him a helpfully controlled variable.
Often, Cousins will begin a play with an immediate read, called an “alert.” For a common example, if the defense blitzes, Cousins will pull out of the progression and throw a pass that punishes that blitz.
[videopress fuR9bxhy]After that point, the rest of the progression is informed by the fact that there is no blitz. If there were, we wouldn’t have gotten to that point. So the rest of the play can be comfortably designed for a non-blitz environment. This is why “getting pressure with four” is so oft-repeated by TV analysts. At this point in the play, it must be taken as a given that at least seven defenders will be in coverage. Knowing that helps to design the next portion of the read.
[videopress dWFPYHIm]If the defensive coverage addresses the short middle with no blitz, it’s likely a 2-hi coverage. That means Cover 2 or Cover 4. Against those, a “Hawk” or “Ohio” route concept is likely to be successful. It’s not the best against man coverage or Cover 3, but against those coverages, we wouldn’t have gotten this far into the read. Here, the Seattle Seahawks show only one high safety but play a modified version of Cover 4 with man-match concepts. It’s a defense that beats many things, but once we’ve sorted out the blitz and several coverages, our odds get a lot better.
Simply running “Hawk” against a random defense isn’t comprehensively successful. But running “Hawk” against a defense that we know isn’t a blitz or Cover 3 is a much better bet. By designing and reading plays with this Bayesian idea in mind, most coaches and quarterbacks can remove the element of surprise. With each layer, the odds increase that they’ll have a counter to the defense’s play call worked in.
Perhaps the Minnesota Vikings could use some more complex ideas, with all the continuity on their roster from 2020 to 2021. A new offensive coordinator is unlikely to install a brand new scheme or core terms, so they could afford to up the complexity a bit. The 2020 Vikings used a lot of “mirrored” concepts, pictured below. These are simple to run but also simple to defend. An example:
In 2021, the Vikings could lean on their quarterback’s in-structure prowess by simply expanding the structure. By adding more layers that narrow down the possible counters, they could be more prepared for varied defenses. They could use the right side and left side of the field to layer in additional contingencies. That wouldn’t require moving on from their heavy outside zone, play-action approach. It would juice up their straight drop-back passing game and increase their chances when behind the 8-ball. Crucially, the players are set up to handle that.
