Kansas City Chiefs: Sizing Up the Long Odds for a Perfect Season

The Kansas City Chiefs take a perfect 9-0 record into their bye week. However, some football experts consider them to be one of the worst undefeated teams in National Football League history for many reasons, including a below-average offense.

The Chiefs have had an easy schedule so far. Their opponents this season have had an average 40 percent winning percentage, the second-easiest schedule in the AFC. That easy ride is quickly going to end as the team faces the third-toughest AFC schedule in their remaining games, against opponents boasting a 61 percent winning percentage.

The first test comes against the Chiefs’ highly regarded division rival, the Denver Broncos, whom many consider to be the league’s best team. Several forecasters pick the Broncos as the favorite to win this season’s Super Bowl, which makes the Nov. 17 matchup a true test for how good the Chiefs are.

If they can get past the Broncos, how long can the Chiefs stay undefeated? Is there any chance of them going 16-0?

The simplest way to estimate this probability would be to consider each game a 50-50 coin flip. The chances of the Chiefs staying undefeated would be 50 percent after one week, 25 percent after two weeks, and so on. Using this estimate, the Chiefs only have a 0.78 percent chance—or 50 percent to the power of 7—of staying undefeated for seven more games.

We know the outcome of football games is not a coin flip, however, so let’s consider a more advanced method of prediction. Brian Burke, founder of the aptly named site AdvancedNFLStats.com, calculates the expected win probability for the Chiefs over their final seven games, based on a variety of factors that include measures of team efficiency, strength and weaknesses on offense and defense, and the effect of turnovers.

Here you see the Chiefs are favored in five of their final seven games, but are the underdogs in both games against Denver. In fact, their very next game, on the road in Denver, is the one they are most likely to lose. Burke’s model only gives them a 24 percent chance of winning that game.

When you accumulate these probabilities, Burke’s model suggests the Chiefs only have a 5 percent chance of getting through the next two games intact. The Chiefs only have a 0.60 percent chance of making it to 16-0. Surprisingly enough, that almost matches the 0.78 percent we got above assuming every game was a coin flip.

The chances seem slim for the Chiefs to make it seven more weeks without a loss, let alone two weeks or even one week. So how have the Chiefs managed to be perfect thus far?

According to Burke, “A big part of their success is due to winning the turnover battle, and getting defensive takeaways in particular, which is the most random component of the game.” He also points out their “soft schedule so far” as well as “a solid defense combined with a conservative, low-risk offense.”

Most simply, Burke says, “the Chiefs have been a combination of good and lucky.”

We’ll find out very soon how much luck they still have.

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