# The Patriots Have a 4.3% Chance of Going 19-0

By Harrison Chase and Austin Tymins

After the Patriots narrowly escaped the Meadowlands with a win this Sunday afternoon, Ian O’Connor of ESPN suggested that readers would be smart to bet on the Patriots going 19-0, saying, “They are still better than everyone else and a much safer bet to go 19-0 than to crumble along the way.” However, anyone that understands basic NFL probability knows this is an absurd statement. Using our POWER Rankings, we can infer the probability that the Patriots will win the remaining scheduled matchups in the regular season to show just how wrong O’Connor is.

Our updated POWER rankings heading into Week 11 are listed below:

With our quantitative measure of team quality, we can find the probability of the Patriots winning each of their remaining matchups. The table below shows the probability the Patriots win each game according to our model. We used our rankings and the log5 method to find the neutral site probability and then adjusted accordingly for home field advantage.

There have only been 15 teams in NFL history to be undefeated through Week 10, including this year’s Patriots and Panthers. And only in 1999 and 2009 have multiple teams in the same season been undefeated at this point. Using the same method, we also looked at the Panthers remaining schedule and win probability in these games as well.

While doing the same process with 538 win probabilities gives the Patriots a 19% chance of going undefeated in the regular season and the Panthers an 11% chance you can see in the table below that we aren’t nearly as optimistic. The Patriots have a slightly easier strength of schedule than the Panthers, mostly due to playing in the AFC. We give the Patriots a 13.42% chance, and the Panthers a 4.76% of finishing the regular season 16-0. See the table below for full probabilities from our model.

To have a 50/50 chance of going 19-0 (an even bet as O’Connor suggests), the Patriots need to be ~93% favorites in every single game including the playoffs. Our model predicts that they will not even hit 93% win probability in any of the remaining games, although they will come rather close to that number in Week 14 against the Titans.

To find the probability that each team finishes 19-0 we made some assumptions about the teams each will play in the playoffs. We used the current playoff bracket as if the season were ending today for our calculations. This means the Patriots are expected to play the Steelers, Bengals, and Panthers while the Panthers play the Giants, Cardinals, and Patriots. Using this method, the Panthers have a .069% chance of completing a perfect 19-0 season while the Patriots have a 4.33% chance. While a 4.3% probability is nothing to scoff at, it is nothing near the 50% probability that Ian O’Connor implied in his article. If anyone would take O’Connor’s side of this bet straight up, we highly recommend taking it!

EDIT: Updated to clarify that the 19% figure we quoted from 538 was based on their win probabilities, not their simulation. Their simulation, which gives the Patriots a 22% percent of going undefeated in the regular season, updates after each simulated game and therefor returns a higher probability then when we don’t update.