What's the Probability an NFL Team Goes Undefeated or Winless This Season?
When the New England Patriots kick off the 2017 NFL regular season Thursday night against the Kansas City Chiefs, they'll also begin yet another title defense. The odds are also in favor of quarterback Tom Brady and his squad winning the Super Bowl again this year, and the numbers back that up.
By our metrics, the Patriots have an 84.1 percent chance of making the playoffs and a 17.1 percent chance of hoisting the Lombardi Trophy. How lopsided is that compared to the rest of the league? Well, no other team has higher than 57.0 percent and 6.6 percent odds, respectively, in each of those categories.
When looking at New England's 9.22 nERD score -- our team efficiency metric where an average team is at 0.0 -- it's clear that they're head-and-shoulders above the competition. The Dallas Cowboys rank second behind the Patriots with a nERD of 4.30, meaning that New England would be about five points better than the NFL's second-best team on a neutral field.
That's all awesome, but on the other end of the spectrum is the New York Jets. They're not the worst team in football based off nERD (they're the third worst), but public perception has them behind our 32nd-ranked team, the Cleveland Browns.
Due to these two extremes, there has been talk about the possibility of both an undefeated season in Foxborough and a winless season in the Meadowlands. But how much of a possibility is there? We can take a look at some numbers to see how likely it is for these two outcomes to actually come true by using our win probabilities for each game.
The Road to 16-0
The first thing that stands out about the Patriots is that they're currently favored to win every game this season. At the moment, their lowest win probability is 61.1 percent, which would be on the road against the Denver Broncos. A lot can happen between now and Week 9 to change those odds, but it's still awfully impressive.
Plus, a 61.1 percent chance of winning still means there's a 38.9 percent chance of a loss. And if last season taught us anything, it's that probabilities are just probabilities, not anything set in stone.
That's why there's not a high chance of New England finishing the regular season 16-0 (again), which can be seen in the table below.
| Week | Opponent | Win Prob % | Undefeated Prob % |
|---|---|---|---|
| 1 | KC | 70.8% | -- |
| 2 | at NO | 61.9% | 43.8% |
| 3 | HOU | 79.6% | 34.9% |
| 4 | CAR | 76.2% | 26.6% |
| 5 | at TB | 64.5% | 17.1% |
| 6 | at NYJ | 73.2% | 12.6% |
| 7 | ATL | 72.5% | 9.1% |
| 8 | LAC | 73.5% | 6.7% |
| 9 | BYE | -- | -- |
| 10 | at DEN | 61.1% | 4.1% |
| 11 | at OAK | 68.3% | 2.8% |
| 12 | MIA | 77.1% | 2.2% |
| 13 | at BUF | 64.8% | 1.4% |
| 14 | at MIA | 67.6% | 0.9% |
| 15 | at PIT | 62.9% | 0.6% |
| 16 | BUF | 74.6% | 0.4% |
| 17 | at NYJ | 81.0% | 0.4% |
The likelihood of this happening drops below 10.0 percent by Week 7, and it dips below 1.0 percent by Week 14. Once again, being favored in every game doesn't mean a victory is always certain, and that's why the Pats currently have a 0.4 percent chance of not losing a single game by the time Week 17 is in the books.
Seeking a Win
Despite all this negative talk about the Jets, our odds currently have them favored to win two games, which are both early in the season.
The first comes at home against the Jacksonville Jaguars, who are 26th by our preseason nERD projections. New York heads to Cleveland to face the Browns the following week, owning just a 52.2 percent probability of winning.
As we can see below, those two games quickly tank the Jets' chances of going winless.
| Week | Opponent | Win Prob% | Loss Prob% | Winless Prob % |
|---|---|---|---|---|
| 1 | at BUF | 17.8% | 82.2% | -- |
| 2 | at OAK | 34.1% | 65.9% | 54.2% |
| 3 | MIA | 46.3% | 53.7% | 29.1% |
| 4 | JAX | 51.5% | 48.5% | 14.1% |
| 5 | at CLE | 52.2% | 47.8% | 6.7% |
| 6 | NE | 26.8% | 73.2% | 4.9% |
| 7 | at MIA | 37.2% | 62.8% | 3.1% |
| 8 | ATL | 39.5% | 60.5% | 1.9% |
| 9 | BUF | 44.0% | 56.0% | 1.1% |
| 10 | at TB | 35.3% | 64.7% | 0.7% |
| 11 | BYE | -- | -- | -- |
| 12 | CAR | 44.5% | 55.5% | 0.4% |
| 13 | KC | 41.3% | 58.7% | 0.2% |
| 14 | at DEN | 31.2% | 68.8% | 0.2% |
| 15 | at NO | 30.1% | 69.9% | 0.1% |
| 16 | LAC | 44.9% | 55.1% | 0.1% |
| 17 | at NE | 19.0% | 81.0% | 0.05% |
It also should be noted that the Jets have attempted to improve their offense a bit over the past week. They've added two new receivers in Jermaine Kearse and Jeremy Kerley, and while making a move like this with a week before the start of the regular season might not be great for team chemistry, it at least gives hope for some sense of competence on that side of the ball later on in the year.
Talk has been focused around both the Patriots and Jets running the table in opposite ways, but the numbers tell us that seeing an undefeated or winless season in 2017 is highly unlikely. That might disappoint some, but the more important thing to remember is that football -- both the good and bad -- is back.
