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Monday, October 1, 2012
Data questions Panthers' choice to punt

By Hank Gargiulo

George Gojkovich/Getty ImagesRon Rivera’s decision to punt isn’t supported by the numbers.

Facing a fourth-and-1 from the Atlanta Falcons ’ 45-yard line late in the fourth quarter against Atlanta on Sunday, the Carolina Panthers chose to take a delay of game penalty and punt the ball away rather than going for the first down.

With the clock under two minutes and the Falcons without a timeout, a first down would have essentially sealed the victory for Carolina. The decision backfired after Matt Ryan led the Falcons down the field into position for the game-winning field goal.

Using ESPN Stats & Information’s win probability tool, the numbers don’t support Ron Rivera’s decision.

As a reminder, our win probability tool uses 10 years of NFL play-by-play data to estimate the likelihood that either team will win at any point in the game, based on historical results in similar game situations. This takes into account factors like time, score, and possession.

Before taking the delay of game penalty, the Panthers had a 90.9 percent chance to win based on their current situation (fourth-and-1, 1:10 left in the fourth quarter, etc.).

At this point, Carolina had two choices.

Choice #1: Go for the first down
This choice, of course, leads to two potential outcomes: convert the first down or turn over on downs.

Since 2001, the league average conversion percentage for teams that go for it on fourth-and-1 in the fourth quarter with the lead and the ball between the 40-yard lines is 71.9 percent. With Cam Newton, Carolina is 4-5 in fourth-and-1 situations).

Using this number we can find the expected win probability for Carolina if it had chosen this option.

By converting the first down, the Panthers would have had a 99.1 percent chance of winning. If they’d gone for it and failed, the win probability would have fallen to 42.0 percent.

Based on those two numbers, going for the first down gave them a 83.5 percent win probability.

Choice #2: Punt
For this option, we used data since 2001 to get the net punt average of 31 yards for all punts between the 40- and 50-yard lines. This means the expected field position of the Falcons after the punt (and delay of game penalty) is their own 19.

This situation -- Falcons with first-and-10 from their 19, with 0:59 left in the fourth quarter -- would give the Panthers a win probability of 57.4 percent.

Thus, by choosing to punt on fourth down the Panthers decreased their win probability by 26.1 percentage points.

As it happened, the punt went as well as possible, as the Panthers downed the ball at the Falcons’ 1.

According to the Elias Sports Bureau, no other team in the past 20 years has conducted a game-winning drive starting inside their own 5 with less than one minute to play.