Which teams got it right on fourth-down and 2-point conversion calls in Week 10 of the 2021 NFL season -- and which teams got it wrong? The Next Gen Stats analytics team uses the Next Gen Stats Decision Guide powered by AWS to break down the numbers behind the decisions that shaped the game.
Mike Zimmer gets every call right in road win
Zimmer and the Vikings have quietly been among the sharpest NFL teams on fourth down this season. Across 51 fourth-down situations when the optimal choice helped the team's chances of winning at a greater rate than one percentage point, Zimmer has made the correct decision 86.3 percent of the time (44 times), the best mark in the league this season and a figure up significantly from Zimmer's effort last season (69.1 percent, 25th-best in 2020).
Getting all seven decisions correct on the road against a coach with proven fourth-down shrewdness is a good way to give your team the best chance to win. Really, though, the defining moments of the game came in two second-half decisions to keep the offense on the field. The latter of the two clinched the win for Minnesota in the game's final minutes.
FOURTH QUARTER: With 2:32 remaining and the Vikings (leading 27-20) facing a fourth-and-2 from the Chargers' 36-yard line, Dalvin Cook picked up a game-sealing first down (4-yard gain).
If the Vikings' offense converts, the game is virtually over. If the unit fails? The team's chances of winning drop to 85 percent, according to the NGS win probability model. By combining each possible outcome with the chances of each happening (i.e., Minnesota had a 55 percent chance of converting in this situation, compared to a 44 percent chance of making a 54-yard field goal), we find Zimmer made the optimal decision in keeping his offense on the field in this situation, by a factor of 2.9 percentage points in expected win probability value.
It wasn't the only go for it decision the Vikings got right on the day. Zimmer kept Kirk Cousins and the offense on the field earlier in the game (with 2:39 remaining in the third quarter) on fourth-and-goal from the Chargers' 1-yard line. The play resulted in a touchdown catch for Tyler Conklin -- and goes down as this week's most obvious go for it call, defined as the decision with the biggest difference in win probability value between going for it and kicking it. In Zimmer's case, going for it increased the Vikings' chances of winning by 11.7 percentage points: 47 percent if they went for it; 35.3 percent if they kicked it.
Brandon Staley makes suboptimal call to kick field goal near goal line
Last week, we highlighted Staley's savvy decision-making on fourth down in his first season as a head coach. This week, however, Staley was more conservative when the numbers said go. Staley made two suboptimal fourth-down decisions when the numbers suggested going for it was the optimal call by more than two percentage points -- these two decisions netted a loss of 6.6 in expected win probability value, which included a costly decision late in the fourth quarter that cost the team 5.4 percentage points in win probability.
FOURTH QUARTER: With 4:40 remaining and the Chargers (trailing 27-17) facing a fourth-and-2 from the Vikings' 6-yard line, Dustin Hopkins makes a 24-yard field goal.
So far this season, there have been 10 situations where a team faced a fourth down when trailing by 10 points in the second half and the NGS Decision Guide recommended going for it by more than two percentage points in expected win probability value. Staley's decision here is one of the four where the coach made the suboptimal call and took three points.
It can seem intuitive that a coach faced with a similar fourth-decision to Staley and Co. (trailing by 10 points in the second half) will choose the option that gives his team the best chance of making it a one-score game. By such logic, a field goal try would feel like the right choice. However, even if the field goal is made, the team has to get a defensive stop, score a touchdown, get another stop and hope to win at the end of regulation or overtime. Rather, if a team is in a territory with a high-probability conversion rate -- like the Chargers faced near the end of regulation against the Vikings (a 58 percent proposition on fourth-and-2 from Minnesota's 6-yard line) -- and the time limits the number of possessions left in the game, going for it can often be the non-obvious optimal decision.
Ron Rivera keeps offense on field in game-clinching goal-line situation
Rivera and the Washington offense faced four different fourth-down situations where the numbers said to go for it. Rivera and his staff made two suboptimal decisions to start the game -- losing 7.7 percentage points in win probability value across two first-quarter field goal tries -- but more than made up for it over their next two go for it tries.
SECOND QUARTER: With 14:15 remaining in the half and Washington (leading 6-0) facing a fourth-and-3 at the Buccaneers' 28-yard line, Taylor Heinicke completes a 4-yard pass to J.D. McKissic to convert.
After making two conservative fourth-down decisions in the first quarter (both fourth-and-4 opportunities inside the Bucs' 30-yard line), Rivera had another chance to be appropriately aggressive on fourth-down (this time, it was a 1.9 percent recommendation to go for it). Rivera correctly kept the offense on the field; and the decision paid off. Heinicke's completion to McKissic set up a touchdown three plays later.
FOURTH QUARTER: With 31 seconds remaining and Washington (leading 23-19) facing a fourth-and-goal from the Buccaneers' 1-yard line, Antonio Gibson rushes to the left end for the touchdown.
In the final minute of the game, Rivera once again kept his offense on the field. If the unit scores, Washington wins. If the play fails, the chances of winning are still quite high (97.6 percent win probability). Washington was able to seal the game with a walk-in touchdown, keeping the ball out of Tom Brady's hands late in the game.
Sean Payton gets conservative near goal line
We highlighted Payton in last week's fourth-down superlatives piece for his savvy in short-yardage situations; Payton was one of three coaches to correctly go for it on 100 percent of short-yardage situations where the NGS Decision Guide recommended to go for it (6 for 6). In the Saints' Week 10 loss to the Titans, however, Payton made his first suboptimal call in a short-yardage fourth-down situation (i.e., 2-or-fewer yards to go). Payton's decision to kick a field goal -- instead of going for it -- cost the Saints 4.2 percentage points in expected win probability value in a game lost by just two points.
FOURTH QUARTER: With 5:35 remaining, the Saints (trailing 23-12) elect to kick a 20-yard field on fourth-and-goal from the Titans' 1-yard line. The kick by Brian Johnson is good.
Trailing by 11 late in the game, New Orleans needed to score twice to pull off a fourth-quarter comeback. So Payton chose to kick a short field goal, bringing the Saints within one possession but costing the team five percentage points of win probability. This decision was suboptimal because it limited New Orleans' chances to win, since the team would only be able to tie the game with a touchdown and two-point conversion on their next possession (assuming the Titans did not score).
The NGS Decision Guide recommended that Payton attempt to convert the fourth-and-goal partly due to a 53 percent chance of conversion, but also because a touchdown would have given New Orleans the opportunity to go for two early. That early two-point attempt would allow the Saints to know whether they would need a touchdown (to win in regulation) or a field goal (to tie), assuming the Titans' score remained the same. Thus, a successful conversion opened a path to a regulation victory, whereas the field goal made that possibility incredibly unlikely.
While a failed fourth-down conversion likely would have ended New Orleans' comeback bid anyway, a field goal gave the team a slimmer chance at victory than it already had. The Saints would ultimately score with just over a minute to go, but then failed to convert the two-point attempt.