Numbers suggest that the Patriots should be more aggressive on fourth down

The New England Patriots have a long to-do list heading towards the 2021 season. Coming off a 7-9 campaign that saw them miss the playoffs for the first time in 12 years, they need to make decisions on their key free agents, upgrade their talent at some key positions on offense and defense, and — Oh, by the way! — find their quarterback of the future.

While those are the big issues that need to be addressed over the coming months, the Patriots also have to take a look at some smaller areas. As Bill Belichick pointed out during his final media conference call of the season, this is something the team does on a regular basis.

“We’re always trying to improve the team in any way we can, whether that’s a play, a technique, a personnel decision, whatever it is, and we evaluate every single thing that we do,” the Patriots’ head coach coach said earlier this month. “We evaluate it on a regular basis. Some things are done weekly, some things are done monthly, some things are done at the end of a particular period of activity as we go through a normal year cycle.”

One of those points that should need to be addressed now that the season is in the books is fourth down aggressiveness. Just look at the following chart illustrating which teams went for it when they should:

Ben Baldwin/Fourth Down Decision Bot

The data used as the basis for this graph comes via the Fourth Down Decision Bot created by Ben Baldwin of The Athletic. Based on the context surrounding the situation, the bot calculates which decision a teams should make when facing a fourth down: go for it, kick a field goal, or punt (depending on the field position only two might make sense).

The following methodology is used to come to those results:

The backbone of these calculations is the win probability model [...] and has the following inputs: seconds remaining in the half and game, yard line, expected points, score differential, down, yards to go, timeouts remaining for each team, whether the team with the ball will be receiving the second-half kickoff later, which team is at home and pre-game point spread.

Going back to the graph above with all this in mind, we can see that the Patriots are ranked in the bottom half in the league when it comes to aggressiveness on fourth down. They have a “go rate” of roughly 33 percent in the appropriate situations where attempting the fourth down versus a punt or field goal attempt would have been the better call from a purely statistical perspective.

21 other teams have had a better rate, including 11 of the 14 that made the playoffs. While aggressiveness on fourth down does not stand in a clear correlation to winning games, it could put teams in better positions to do so.

The Patriots, for example, have lost a combined expected winning probability of 41 points by opting to kick rather than go for a conversion:

Ben Baldwin/Fourth Down Decision Bot

Sure, there are factors the numbers simply cannot measure — like the quality of players involved in a certain play (e.g. punter and punt returner) — and the science itself can never be a 100 percent exact one. There are tendencies that can be identified, however, and those might just give teams a basis to self-scout heading into the offseason.

The Patriots are in such a spot: they have potential for more fourth down aggressiveness, and to improve the process they have in place to make those decisions.

Of course, this is all but one part of the big mosaic that is getting better during the offseason. Another big one, for example, is acquiring or holding onto players that give the coaching staff confidence to make such “Go for it!” calls. Whether or not that was always the case for the Patriots in 2020 can be questioned considering the offense’s overall output and general inconsistency, but the numbers do suggest there is room for improvement regardless.

Looking at the Patriots heading into the 2021 offseason, the two might therefore go hand-in-hand. One goal should be to improve the offense by getting better production out of positions that have struggled in 2020, like quarterback and wide receiver. Once that is achieved, though, the work is not done: New England also should try to improve the fourth down numbers illustrated above in a follow-up step.