In their come-from-ahead loss to the Atlanta Falcons on Monday night, the Philadelphia Eagles made a crucial error. Up by three points late in the game and facing fourth-and-3 from the Atlanta 10-yard line, Eagles head coach Nick Sirianni opted to kick a field goal and put his team up by six points with a minute and 39 seconds remaining.
On first glance, this is a reasonable enough decision. The Eagles made a field-goal game into a touchdown game, after all. But that is too simplistic a framework for the decision.
There's a reason that almost every fourth-down model in existence favored going for it on fourth down over kicking the field goal. NFL.com's NextGen Stats model, for example, dropped the Eagles' chances of winning the game from 94% to 85% after the kick. ESPN's model favored going for it over kicking on anything less than fourth-and-9. The NFL4th.com bot created by Ben Baldwin had a "strong" lean toward going for it as well.
Though those models are analytics-based, the reasoning behind the numbers actually has more to do with the human element often cited as a reason for more conservative decision-making.
Teams down by three points late in games will most often play for three points, seeing their goal as tying the game in order to take it to overtime, where their chances are something like 50-50. Teams down by six points know they have to play for a touchdown, and are therefore more aggressive about trying to score.
The team with the lead is still overwhelmingly likely to win; they are still up by six with very little time remaining, and the trailing team often has to go 70-plus yards without any timeouts to get to the end zone. But the decision extend the lead to a touchdown, but actually less than a touchdown because teams are almost certain to convert extra points, actually gives the trailing team a better chance to win the game in regulation than it would have if only trailing by three.
And of course, even assuming that the trailing team would have a chance to get the ball down by three necessitates assuming that the leading team would fail on fourth down. In reality, NFL teams are getting better and better at converting fourth-down opportunities. Over the last five years, teams that go for it on fourth-and-3 or less while leading in the fourth quarter have converted more than 50% of the time. That's more than enough to justify the decision to go for it in that situation -- especially considering the psychological impact on the trailing team's approach in that even that the fourth-down chance fails.