The new overtime rules (though not entirely too new at this point) are intriguing, for sure. Once both teams have been given the right to “possess or have the opportunity to possess the ball,” then the game turns into sudden death. Prior to that, a touchdown wins the game, while a field goal gives the other team one possession to tie it (as in the case of the Vikings – Packers game earlier this season) or win it with a touchdown.
The one loophole in this is the way that the league determines the “opportunity to possess the ball.” According to Approved Rulings 16.2 and 16.3, an onside kick that is recovered by the kicking team means that the original receiving team has had the opportunity to possess. In short: kick an onside kick, if you recover it, you only have to score a field goal. If you don’t recover it, you are not considered to have had your opportunity to possess, and thus the game will go on if the receiving team goes on to kick a field goal.
This leads to the inevitable question, “Yes, but now you’ve given your opponents great field position in the event that they recover the onside kick.” With the help of our friends over at Advanced NFL Statistics, we’re able to analyze the validity of this concern.
According to their Win Probability Calculator, the likelihood of a team scoring a touchdown when starting OT at their own 20 is approximately 15%. If that same team starts at the opponent’s 45, the touchdown probability only increases to 28%. This means that a team is only assuming 13 percentage points of additional risk in the onside kick attempt.
Now, to offset that risk, the balance of reward. With the receiving team having had the “opportunity to possess,” the kicking team only needs a field goal to win. Assuming that they start with the ball at their own 45, the probability of a touchdown is 23%, and a field goal is 16%, for a total probability of a game winning score of 39%.
Given the risk of 13% and the overall reward of 39%, this means that if greater than one in four onside kicks is successful, a team will be better off. In 2013, the success rate of an onside kick sits at almost 22% (12/56 by my calculations), while surprise onside kicks (let’s just say any onside kick not in the 4th quarter) succeed 67% (4/6, sample size warning!) of the time. An onside kick at the beginning over overtime would certainly be unexpected (at least the first time.)
So why don’t coaches do it? Like most things, it comes down to the “gaffe factor.” Those less familiar with the numbers (the fanbase as a whole, generally) would say if an attempt were to fail that it was an unnecessary risk, despite the fact that it is the smart move. However, given that Week 17 is coming up and there are some coaches fighting for their jobs (or, in the case of Mike Shanahan, fighting to lose it), perhaps the time is now for the overtime onside kick.