The Improbability of the Cleveland Browns’ Winless Streak

By: Jack Schroeder

Thursday night, the Cleveland Browns beat the New York Jets 21-17, their first win since beating the then-San Diego Chargers on Christmas Eve in 2016. The Browns’ winless streak stretched 635 days. To put that in perspective, when the Browns last won a game, Barack Obama was still president, “Black Beatles” was the #1 song on the Billboard Hot 100, and Colin Kaepernick still played in the NFL. While the Browns have been subpar almost my entire life, I wondered how unlikely their nineteen-game winless streak really was.

To find an answer, I compiled the Elo ratings of the Browns and their opponents for every game of the winless streak. I retrieved this data from FiveThirtyEight. Elo is a statistical measure of team strength originally developed for chess. An Elo rating of 1500 is considered average. Teams will gain or lose points in their rating based on the games they play, and because Elo is a closed system, points gained by one team are lost by another. Elo is not without its flaws: most notably, it fails to compare opponents over time. To avoid this, I took each matchup’s Elo ratings as they were before that week of play had started.

The Browns were a bad team by Elo standards before their streak began. Their rating of 1253 leading into their first loss was the worst in the league by 257 points. Save for 2 preseason boosts (Elo scores move back toward the mean before each season), their tie against the Steelers was the only time the Browns’ Elo increased during the streak. Even at their peak Elo of 1336, the Browns were still the worst team in the NFL.

The Browns never came close to meeting the average Elo of 1500. When compared to the Elo of their opponents, it almost makes sense the Browns would fail to win a game.

But Elo ratings themselves fail to do the Browns’ story justice. Using each team’s Elo ratings, I calculated the Elo win probability for each matchup in the streak. To account for home-field advantage, I added 65 Elo points to the home team in each game before calculating the win probability (as FiveThirtyEight does). The Browns were the underdogs in every game they failed to win. Their highest win probability of 40.2% came at home against the Cincinnati Bengals in Week 4 of 2017. The hardest matchup of their streak was against the Pittsburgh Steelers in Week 17 of 2017, where they had a 4.6% chance of winning and avoiding an 0-16 season.

These incredibly low odds were mostly due to the fact that the Browns were very bad during their streak; however, the Browns did have some tough matchups. An average team with an Elo of 1500 would have been favored in 8 of these games. For example, an Elo-average team only had a 21.2% of beating the Steelers at the end of the 2017 season. However, the main reason why the Browns’ schedule looked so daunting was that the Browns were so terrible.

I then multiplied the inverse of the Browns’ Elo win probabilities in each game to determine the overall probability of the winless streak. I also calculated this week-by-week in order to graph the results chronologically.

Overall, the Browns had a 1.3% chance of failing to win any of these nineteen games. This number is strangely high considering the circumstances. For context, this streak was over 160 times likelier than hitting a hole-in-one on a par 3 hole (per Golf Digest). I also plotted the probability of an average team going on the same winless streak to help gauge how unlikely the Browns’ streak was. This calculation is flawed because the average team’s Elo rating should have decreased after each loss, but I am only using this number as context.

The cumulative probability of a winless streak for the average team dropped below 1.3% by the Houston Texans matchup in Week 6 of the 2017 season. From there, the probability of zero wins dropped further until bottoming out at 0.00046%. Writing the number out does a poor job of showing how minute the probability really is. It is over 70 times likelier that I will get struck by lightning in my life than it is for an Elo-average team to have gone on this streak (National Geographic pegs the lightning odds at 1 in 3,000). The probability of the Browns’ streak is over 2,800 times greater than the Elo-average team’s.
This analysis has one major flaw and another area for expansion. The Browns infamously tied the Steelers in Week 1 of the 2018 season, which complicates the odds of the winless streak. However, since I was calculating the odds of the Browns going on a winless streak, and not the odds of losing 17 games, tying 1, and then losing another, I ignored the tie. The average team analysis could be done more effectively in the future. Instead of running a simulation, I used a constant Elo rating of 1500 (while adjusting for home-field advantage). This worked for the article because putting an actual team in the Browns’ shoes would have meant re-calculating Elo ratings after every loss, which would have had reverberations across the league. In the future, however, it would be interesting to see how certain teams would have performed in similar situations.

Overall, while incredibly unlikely, the Browns’ winless streak was still frighteningly plausible. Although Browns fans should celebrate their victory, they are not out of the clear. Cleveland’s Elo rating of 1328 is still the worst in the NFL. Coach Hue Jackson has not committed to starting Baker Mayfield going forward. This is all aside from the fact that Jackson has 2 wins in 35 games as Browns head coach. But Thursday night signified an end to something for the Cleveland Browns. Indeed, their fans now have hope. Whether that hope has been truly earned remains to be seen.

Editors Note: If you have any questions about this article, please feel free to reach out to Jack at jackschroeder@college.harvard.edu

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