In one of the more intriguing match-ups of the weekend, Tony Romo and the Cowboys received the ball in a tie game just over midfield with 0:47 seconds remaining. After two incompletions and one pass to Jason Witten, the Cowboys faced a 4th-and-4 at the Steelers 43-yard line. With 0:32 seconds to go and one timeout left, the Cowboys trot out their field goal team for a miraculous 60-yard game-winning kick. Both teams would call timeout and Jason Garrett would ultimately decide to punt instead, essentially assuring overtime. Let's think about this decision generally before looking at the frequency specifics.
If you punt, you are conceding to play overtime, giving your team a 50/50 shot to win the game. If you kick a field goal from that range, the probability that it goes in is at best the same as the probability that you miss and your opponent can score before the end of regulation, giving you a 50/50 chance to win optimistically. If you go for it and convert, you will have a much higher probability of making the field goal even with time constraints -- if you fail, you are pretty much in the same situation as a missed field goal.
So, with that in mind, here are the numbers:
|Statistic||Go For It||Punt||FG Attempt|
|Win Probability Success||84%||49%||95%|
|Win Probability Fail||36%||-||30%|
|Expected Win Probability||61%||59%||40%|
4th-and-4 converts historically at 53% resulting in an expected 61% for the Cowboys to win the game if they go for it (84% on a successful conversion vs 36% on a failure). A punt results in a 49% chance of winning (likely due to the possibility of a block/botched punt, a return for TD or extremely unlikely case of the returning team scoring after the punt). 60-yard field goals convert at about 15% and a miss would mean a 70% chance for the Steelers to win with approximately 0:25 seconds left on the clock. That makes the break-even point between deciding to punt or go for it a mere 27%. In other words, unless the Cowboys think they can only convert one out of four times or less on 4th-and-4, they should go for it.
Keep in mind, these probabilities are only league-average baselines, so there are definite margins for error. But, the difference between 53% and 27% is extremely significant. One other note is that this analysis assumes an average amount of timeouts left for both teams. In our case, Dallas was out of timeouts and Pittsburgh had one remaining -- most likely about average given the situation. Since it was a tie game and timeouts have a much greater affect on the probability of a team scoring when they are on defense, rather than offense, the timeouts left assumption seems reasonable.
The Cowboys also had a 4th-and-1 from their own 21-yard line right at the two-minute warning. Obviously going for it here is a much riskier proposition -- meaning a much more difficult decision for a coach in the conservative NFL, especially one on the hot seat under Jerry Jones. The numbers say to go for it (as they almost always do on 4th-and-1): Expected Win Probability [Go-for-it] = 49% vs Expected Win Probability [Punt] = 30%. This makes the break-even point 33% compared to league-wide 74% conversion on 4th-and-1. The primary reason is that if you punt the ball back, the Steelers will be in a position to drive down field and take the last possession of the game for a game-winning field goal. Similarly, if the Cowboys convert on 4th-and-1, they would have the same situation. Both teams did have three timeouts at this point, though, which would increase the Steelers chance of winning were the Cowboys to convert and would increase the Cowboys chances of winning on a punt -- since there would be more time left on the clock to respond to a Steelers scoring drive. As such, the 74% to 33% conversion rate to break-even rate discrepancy would likely shrink. Garrett, as expected, elected to punt and Brian Moorman hit a 59-yard boomer.
You can also view this article on Advanced NFL Stats.com.