By Scott Kacsmar
Cold, Hard Football Facts Rational thinker

With the lead in the NFC South on the line, the Atlanfa Falcons faced an interesting decision in overtime against the Saints with the ball at their own 29 and a 4th-and-inches in their way.

That’s when Mike Smith decided to send back the punting team and roll with his offense to gain the one yard they needed.
Michael Turner was stuffed in a heavy-run formation, and the Saints took over at the ATL 29. Drew Brees would only need one completion and two running plays, and John Kasay kicked the 26-yard game-winning field goal.
It’s exactly the kind of call that will get criticized by the crowd at large, especially when it fails, and revered by the statheads. The Captain would like to put himself somewhere in the middle to judge this one. 
Over at Advanced NFL Stats, Brian Burke ran the numbers on win probability (WP) to analyze Smith’s decision. The results, based on averages from all games 2000-2011, ruled in favor of going for it (Atlanta’s WP = 0.47) instead of punting (Atlanta’s WP = 0.42).
At the very least, it proves Smith was not without reason to make the decision. The risk was high as New Orleans would be likely to kick a winning field goal had they failed, but there was also a strong chance (roughly 74% of all 4th and 1 opportunities are converted) Atlanta would gain the yard they needed.
The decision was rational, but that doesn’t mean Smith had to take it. There are many variables at work here, and numbers collected to produce an average situation unlikely don’t perfectly fit the situation of this game.
The Saints rank dead last in yards/carry on rush defense. The Falcons have Michael Turner and a power-running game that ranks 3rd in the league on runs on third and short. The game was in a dome, with veteran kickers on each side. Both quarterbacks passed for over 300 yards and are among the league-leaders in game-winning drives the last few years. The Falcons allow the 6th fewest yards (110) on punt returns this season. Darren Sproles is a very good return man.
That’s only some of the thoughts going through one’s head about the decision. Mathematically, the win probability after punting is based on where the Saints would start with the ball. The average for punting from your 29 leads to the opponent starting on their own 33 with a 1st and 10, thus the 0.42 WP for Atlanta. The problem is this is the only number that’s being used to compare the decision to punt, and that figure is simply the average.
This game actually offered three different examples of Atlanta punting from a very similar field position to where they were when they went for it (4th and 1 at the ATL 29).
Atlanta's Punts
QT Down-Distance LOS NO Start ATL WP
1 4th & 1 ATL 29 22 (no penalty) 0.51
1 4th & 1 ATL 29 10 0.65
2 4th & 1 ATL 29 36 (no penalty) 0.39
2 4th & 1 ATL 29 48 0.31
OT 4th & 2 ATL 28 27 0.46
On the first two punts, a penalty was called. The first was on the Saints, pushing them back to the 10. The second was on Atlanta, moving the ball ahead to the NO 48. In the first case, Atlanta would have had a better chance of winning than going for it, had the punt pushed the Saints back to their 22 or 10. The second time, the Saints had the advantage, penalty or not. Then the third time was all but a wash with going for it, which just goes to show a couple yards on the punt can make up the 0.05 difference in win probability.
For what it’s worth, the Saints went three and out after all three of these drives. You never really know for sure what’s going to happen, but Mike Smith probably knew the backlash would be coming if this didn’t work, and unfortunately for him (and for the advancement of more decisions like this), it didn’t work.