Down 17 to 14 with 2:52 left to play, the Falcons faced a 4th and 6 from their own 43-yard line. With two timeouts and the two-minute warning in their pocket, they chose to punt, hoping to make a stop and get the ball back with enough time to tie or win in a final drive.
Did head coach Mike Smith make the right call?
A punt in this situation typically nets 37 yards, which would give the Saints a first down at their own 20. This would give the Falcons a 0.15 Win Probability (WP).
Fourth-and-6 attempts outside the red zone are successful about 44% of the time. A success gives the Falcons a first down at (at least) their 49-yard line, worth 0.37 WP. A failure giving the Saints the ball at Atlanta's 43 would mean a 0.12 WP for the Falcons. All would not be lost. A stop or even allowing a FG still gives the Falcons time for a TD drive, which when all four downs are available are successful more often than many realize.
In total, the fourth down conversion attempt would be worth:
0.44 * 0.37 + (1 - 0.44) * 0.12 = 0.23 WP
The conversion attempt would have been the percentage play, by a margin of 0.23 to 0.15. In fact, in terms of WP, it's more than half-again better than punting. One way to think of it is that the Falcons' decision to punt lopped between a third and a half off of their chance of winning.
I think game-specific considerations would tend to favor going for the conversion and keeping the ball out of the Drew Brees' hands. Normally offenses ahead in that situation are very reluctant to do anything but run straight ahead, making them predictable and easy to stop. But the Saints trust Brees to make completions. In any case, neither team was playing far from league-average Monday night, with a total of 31 points on the board.
Ultimately, the Falcons allowed two first downs and never got the ball back, falling 17-14.