Which teams got it right on fourth-down and 2-point conversion calls in Week 14 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.
Sean McDermott made the right call to kick game-tying field goal
At halftime of this matchup, the Next Gen Stats win-probability model gave the Bills, who were trailing by 21 points on the road against a Bucs team that had won all five home games entering Sunday, a 5 percent chance of achieving victory -- and that mark dipped even lower (to 2 percent) early in the fourth quarter. Instead of slinking away, Buffalo stormed back, scoring 17 answered points in the last 10 minutes of regulation and sending the game into overtime with a last-minute field goal.
Wondering whether McDermott should have gone for the win instead? Let's break down the numbers:
FOURTH QUARTER: With 25 seconds left and the Bills (trailing 27-24) facing a fourth-and-2 from the Buccaneers' 7-yard line, Tyler Bass makes a 25-yard field goal.
The NGS Decision Guide strongly agreed with McDermott's decision to kick a field goal, favoring it by 3.4 percentage points in expected win-probability value. The Bills had a 53.6 percent chance of picking up the first down if they went for it, but a failed conversion would have ended the game in a Buffalo loss. Plus, even if the Bills had successfully converted, they were out of timeouts, meaning Josh Allen and Co. would have needed to rush to spike the ball and stop the clock, assuming they didn't score on the play. The upside of going for it was limited, given that the Bills would still only have a 73 percent win probability if the offense gained the necessary yards to gain without scoring, while the downside was a guaranteed loss.
As they say, football is a game of inches, and it's worth noting how the equation would change if the Bills had the ball closer to the sticks. If the Bills had just 1 yard to go instead of 2, their conversion probability would rise from 53 percent to 70 percent -- making the go for it choice a more valuable proposition than the field goal (by 3.6 percentage points in expected win-probability value). The Bills' conversion probability would rise to an even higher number of 77 percent if the situation was a matter of inches, and going for it would have carried an advantage in win-probability value of 9.9 percentage points.
Kyle Shanahan and Zac Taylor stay conservative in near-tie
Across all fourth-down decisions this season when the numbers say go for it by at least 1 percentage point in win-probability value, the Bengals' Taylor has lost the third-most total win probability (-0.53), while the 49ers' Shanahan has lost the sixth-most (-0.41). The trend continued on Sunday, with Taylor (four) and Shanahan (two) combining to make six suboptimal decisions to kick; Shanahan lost 5.0 percentage points in win-probability value, and Taylor lost 11.7.
Let's first dig into a decision made by the winning side:
FOURTH QUARTER: With 2:47 remaining and the 49ers (leading 20-13) facing a fourth-and-2 from their own 37-yard line, Mitch Wishnowsky punts 50 yards to the Bengals' 13-yard line.
San Francisco had the opportunity to boost its win probability -- which sat at 90 percent here -- to over 96 percent with a first down, given that the clock could only be stopped twice more (via the Bengals' last timeout and the 2-minute warning). The NGS Decision Guide favored going for it by 2.8 percentage points in win-probability value. However, rather than leave his offense on the field, Shanahan opted to punt the ball back to the Bengals. Joe Burrow and the Cincinnati offense proceeded to drive 87 yards on the next possession, culminating in a Burrow-to-Ja'Marr Chase 32-yard touchdown and a game-tying extra point. The 49ers had one more chance to win in regulation, but Robbie Gould's missed 47-yard field-goal try sent the game into overtime.
Shanahan's other suboptimal decision came much earlier in the game, on fourth-and-2 from the Bengals' 15-yard line in the first quarter, when the contest was still scoreless -- kicking a field goal cost the Niners 2.2 percentage points in optimal decision value.
That quarter was when Taylor and the Bengals made an even more costly decision on fourth down:
FIRST QUARTER: With 36 seconds left and the Bengals (trailing 3-0) facing a fourth-and-1 from the 49ers' 19-yard line, Evan McPherson kicks a 37-yard field goal to tie the game.
Out of the four suboptimal fourth-down decisions made by the Bengals on the day, Taylor's decision to kick a field goal instead of going for it here cost the team the most in win-probability value (3.9 percentage points, per the NGS Decision Guide output). When it comes to fourth-down decision-making, especially early in the game, maximizing points is the most advantageous strategy. With at least nine possessions left for either team in the game at this point (using three drives per quarter per team as a league-wide heuristic), tying it up at 3-3 turns out to be the suboptimal decision, given the likelihood that the Bengals would have extended the drive with 1 yard to gain (71%), compared to the likelihood of converting a 37-yard field-goal try (84.5%).
Taylor again passed up on a chance to go for it on a fourth-and-1 situation early in the third quarter, with the Bengals punting from their own 34-yard line while trailing 17-6. The NGS Decision Guide had that decision as a go for it by 2.8 percentage points in win-probability value.
Falcons split fourth-and-1 decisions in the first quarter
In the first quarter of this high-stakes NFC South matchup (per the playoff probability leverage model established by ESPN's Brian Burke, the loser would all be eliminated from playoff contention), Falcons head coach Arthur Smith faced two situations where the numbers recommended going for it by at least 2.5 percentage points -- but he correctly kept the offense on the field just once.
Let's look at these decisions:
FIRST QUARTER: With 12:46 remaining and the Falcons (tied 0-0) facing a fourth-and-1 from their own 34-yard line, Thomas Morstead punts 46 yards to the Panthers' 20-yard line.
Atlanta had a notably high chance of conversion (68%) here, agnostic of play call, with that conversion probability rising to an even stronger 73.5 percent with a run call. However, Smith chose to punt the ball away to end Atlanta's opening drive, rather than risk a failure that would allow the Panthers to start their own opening drive deep inside Falcons territory. Regardless, the NGS Decision Guide disagreed strongly with the decision, estimating that going for it would have increased the Falcons' chances of securing a road victory by 2.6 percentage points. As it was, the Panthers were able to score on the possession and take the lead.
FIRST QUARTER: With 5:47 remaining and the Falcons (trailing 7-0) facing a fourth-and-1 from the Panthers' 31-yard line, Mike Davis rushes for 5 yards and the first down.
With the Falcons trailing by a touchdown on their second drive, Smith again faced a fourth-and-1. Again, the team had a notably high chance of conversion (68%) no matter the play call. Inside Panthers territory this time, Smith correctly decided to keep his offense on the field, increasing his team's chances of winning by 4.5 percentage points. Smith would be rewarded for his optimal decision, with Davis picking up the first. Atlanta tied the game shortly thereafter and never trailed again.