The Falcons Should Have Attempted an Onside Kick to Start Overtime

After losing the overtime coin toss, the Atlanta Falcons were forced to kick off to the New England Patriots to open the first overtime in Super Bowl history. They kicked deep into the end zone, resulting in a touchback and Patriots ball at the 25-yard line. Tom Brady and co moved the ball straight downfield with little resistance and scored a touchdown, ending the game and capping off the largest comeback in Super Bowl history. Kicking deep gave the ball right back to the quarterback many consider the GOAT and sealed the Falcon's fate.

But what if Atlanta had attempted an onside kick?

Per the NFL's current overtime rules, if the kicking team successfully recovers an onside kick the game immediately becomes sudden death:

A.R. 16.2 ONSIDE KICKOn the opening kickoff of overtime, Team A legally recovers the ball at the A41.Ruling: A's ball, first-and-10 on A41. A kickoff is considered an opportunity to possess for the receiving team. Team B is considered to have had an opportunity to possess the ball.

Their decision to kick off resulted in NE with the ball at their own 25, which will serve as our "control scenario", where ATL had a 35.6% chance to win (per Prediction Machine):

There are a couple of scenarios that could have resulted in a Falcons win had they tried an onside kick, so let's run through them and quantify them:

1. Onside kick RECOVERED, ATL Field Goal:

Onside kicks are successfully recovered about 26% of the time overall, but in this case the Patriots would have been caught by surprise, which increases the probability of success. A "surprise" onside kick is recovered by the kicking team around 60% of the time, and this is the number I'll use. 

If the Falcons score at all, the game is over and they're Super Bowl champions. In this first scenario we'll use the chances of their drive (which would start around their own 45 yard-line following the onside kick) ending in a field goal, which is about 19% (sourced from this post by PhD Football, which gauges the percentage of drives that end in a field goal or touchdown based on how many yards to goal remain when the drive starts).

Probability of Scenario #1: 60% * 19% = 11.4%

2. Onside kick RECOVERED, ATL Touchdown:

This also would have given Atlanta their first ever NFL championship. As before, I'm using 60% for the onside kick and then 22% for a possible touchdown (drawn from the above link).

Probability of Scenario #2: 60% * 22% = 13.2%

3. Onside kick RECOVERED, ATL punt/turnover, NE doesn't score, OT continues:

Since 19% of drives from your own 45-yard line end in a FG and 22% end in a TD, 59% end in a punt or turnover. From there, the Pats would have to NOT score, since any points would end the game. I'm making some assumptions with their field position after the punt, but they should get the ball around their own 20, where they would have a 10% chance of hitting a field goal and an 18% chance of scoring a touchdown, meaning they have a 72% chance of not scoring (and the Falcons getting the ball back). For simplicity I assume each team has about a 50/50 shot from here.

Probability of Scenario #3: 60% * 59% * 72% * 50% = 12.7%

4. Onside kick NOT RECOVERED, NE Field Goal, ATL Touchdown:

Not recovering the onside kick is 40%. New England would then have a short field initially, and their chances of getting a field goal after starting at Atlanta's 45 is about 22%. From there, an Atlanta touchdown would end the game. Starting at around their own 25 (after the kickoff) gives them an 18% chance of scoring that TD.

Probability of Scenario #4: 40% * 22% * 18% = 1.6%

5. Onside kick NOT RECOVERED, NE Punt, OT continues:

New England has a 33% chance of scoring a touchdown after getting the ball off of the failed onside kick, and a 22% shot at hitting a field goal (as mentioned previously). Therefore their chances of NOT scoring and punting/turning the ball over are 45%, at which point overtime would continue.

Probability of Scenario #5: 40% * 45% * 50% = 9%

6. Onside kick NOT RECOVERED, NE Field Goal, ATL Field Goal, OT continues:

This is the most unlikely outcome: New England's field goal odds are 22%, and then Atlanta would have to drive to kick a tying field goal after the ensuing kickoff (a 10% proposition). From there the game would continue in sudden death.

Probability of Scenario #6: 40% * 22% * 10% * 50% = 0.4%

I'm not accounting for defensive or special teams scores that would have given Atlanta the title, but the above six scenarios sum up to the following win probability:

11.4% + 13.2% + 12.7% + 1.6% + 9% + 0.4% = 48.4% 

Since our initial "control scenario" was 35.6%, this indicates the Falcons should have attempted an onside kick, which would have increased their win probability to right under 50%.