On his way to winning NFL Coach of the Year in 2013 Ron Rivera’s aggressiveness on 4th-and-1 earned him the nickname “Riverboat Ron.” Four years later in 2017, Doug Pederson and the Philadelphia Eagles made a surprising Super Bowl run, at least in part due to their aggressiveness on fourth down. Their go-for-it rate on 4th-and-1 was the second-highest in the league in 2017.
The analytics movement in the NFL is well on its way, and at the heart of it is the decision of when to go for it on fourth down.
In order to evaluate how well teams are performing on fourth down, we can use Sports Info Solutions’ win probability model to calculate the expected win probability for each of the three options a team has: go for it, attempt a field goal, or punt. The calculation for each is based on the win probability of the expected outcomes in each situation. For example, if a team were to go for it on fourth down, we would calculate the expected win probability in the event they are successful, and the win probability in the event that they turn the ball over on downs, and weight them based on the likelihood of a conversion. If a team had a 55% chance of converting a given fourth down, and the win probability is 62% with a successful attempt and 50 with a failed attempt, the expected win probability would be 56.6. We can write the formula as:
Expected Win Probability = (WP of Success * Chance of Success) + (WP of Failure * Chance of Failure)
In the calculation of a successful fourth down attempt, the minimum successful play is used as the expected outcome, but there are a wide range of outcomes that would be even more valuable. As an example, the Texans scored a 21-yard touchdown on a 4th-and-1 attempt Monday night. Because of this, our method actually slightly undervalues the benefit of going for it.
With all of that in mind, we looked at which teams were the smartest about going for it when it was the optimal choice, essentially looking at which teams were the most aggressive and savvy in their fourth-down decision making. We calculated a team’s rate in 2018, as well as a three-year average. In both cases, we looked only at one-score games with more than four minutes remaining to remove any situations where teams were forced into going for it.
On the aggregate, teams seem to be starting to figure it out. In 2018, all but eight teams were more aggressive than their three-year average. And at least one of the teams, the Eagles, can be forgiven since their 2018 number still landed them as one of the three most aggressive teams on fourth down.
One team that cannot be forgiven is the San Francisco 49ers, who did not go for it on a single fourth down in 2018 in a one-score game outside of four minutes despite the model recommending it 11 times. Their three-year average of 19% also places them in the bottom five of the league. Even though they played most of the season with a backup quarterback and an injury-depleted running back group, it’s still a shocking stat.
While teams are trending in the right direction, the league’s best team in 2018 still only correctly went for it about 64 percent of the time. We will never see a team get to 100, and there will always be factors that can’t be fully accounted for by win probability models, but this still indicates there is a lot of value being forfeited by teams on fourth down.
Teams Need to Go-For-It More in Fourth and Short
On Sunday, the Eagles faced a 4th-and-1 from their own 34 while trailing the Redskins by 13 in the third quarter. The Eagles opted to go for it against conventional wisdom, and Carson Wentz picked up the first down with a two-yard QB sneak. The Eagles would go on to score a touchdown and cut the Redskins’ lead to one score on the drive, and eventually, go on to win the game comfortably. It was a perfect example of where smarter teams are gaining an edge, and where the more resistant teams continue to fall behind.
Using expected win probability, it is almost always optimal for teams to go for it on 4th-and-1 or 2 regardless of where the team is on the field, even accounting for game script. It is understandable that teams are hesitant to pull the trigger from the shadow of their own goal post, but as you get closer to midfield, the decision becomes more and more clear, and teams aren’t taking nearly enough advantage.
4th-and-3 is where things start to get more interesting. Not surprisingly, it is not generally prudent to go for it from your own territory. But as you approach and cross midfield, the expected win probability of going for it surpasses that of a punt. And teams aren’t taking advantage.
On fourth downs between your own 40 and midfield, expected win probability recommends going for it about 48% of the time, meaning the model doesn’t feel as strongly about these situations. But once you cross midfield, the recommended percentage jumps to 96%, and yet, teams only went for it about 13% of the time.
The equation changes a bit once field goals become a legitimate option. Generally speaking, field goals are the better option in these situations until you are approaching the goal line.
Stop Kicking Field Goals from the Goal Line
Probably the most blatant blunder from this past weekend was the Steelers kicking a field goal from the Patriots’ 1-yard line. The analysis of 4th-and-1 in general would have been sufficient in explaining why what the Steelers did was questionable, but if you also consider that the Steelers were trailing the perennial AFC Championship finalists by 20 points, it is even more head-scratching.
In defense of the Steelers, they aren’t the only team that struggles with this. The Rams did something similar, albeit less egregious, in last year’s NFC championship. But they were lucky enough to escape with a win. And this is a conundrum that a lot of coaches are consistently getting wrong.
Since 2016, there have been 118 instances of teams facing 4th-and-goal from the 1. In all instances, the expected value of going for the touchdown was higher than that of going for a field goal. Despite that, teams only went for the touchdown about 81% of the time.
The farther away from the goal line you move though, the more risk-averse teams get. From the 2, the model recommended going for it about 75% of the time, but teams only went for the touchdown about 25% of the time. From the 3, the model recommends going for it about half of the time, but teams only went for it about 13% of the time.
When should you go for it in goal-to-go situations? (2016-2018)
|Yard Line||Recommended %||Actual %||Sample|
One way to explain this is with the expected value of going for the touchdown. Even if you assume a team has only a 50% chance to convert, which is incredibly pessimistic given the historical success rate, the expected value of going for the touchdown is three points, which is marginally higher than the expected value of a field goal given that a successful field goal is not a certainty. It’s the same reason NBA teams have started relying on three-pointers instead of mid-range jumpers and why MLB teams have started looking for home run hitters as opposed to guys who hit for average.
The other part of this is that a team starting from its own goal line has an average Expected Point value of minus-2.2. What this means is that even in the event of an unsuccessful attempt, a team would still be favored to score next, assuming there’s enough time remaining for it to manifest itself.
While most teams finally seem to be moving in the right direction, there is still a lot of value being thrown away with conservative decisions on fourth down. Coaches can be forgiven for not going for it from their own 25, but over the course of the season consistently punting from midfield or kicking field goals on the goal line will cost a team a lot of points.