Is It Hard To Beat the Same NFL Team Twice in the Same Season?

Every year, each NFL team plays each other team in their division twice in the regular season. These divisional matchups are often the source of bitter rivalries between teams in the same division. Think about the Packers and the Bears, or the Patriots and, well, basically everyone in their division.

According to conventional wisdom (or at least, according to my Dad) it’s difficult for the same team to win both of these games. It’s easy to think of reasons why this might be the case. After losing once, a team might adjust their strategy to account for weaknesses, giving them a better chance the next time the teams play. Additionally, when teams play each other twice, the NFL schedule is set up so that each has home field advantage in one game, meaning that wining both games a requires getting a win on the road.

Is the conventional wisdom that it’s hard to beat the same team in one season twice true? To find out, I used the nflreadr package in R to examine all the cases where two teams played twice in the regular season between 2002 and 2022. In each years, there were 48 instances of two games played between the same teams. Looking across 21 years (and excluding 7 instances where one of the games ended in a tie). this leaves a total of 1001 two game matchups.

In 58% of these matchups, the same team won both games. We can see this by season below:

Thus, contrary to conventional wisdom, it isn’t hard to beat the same team twice. Instead, when two teams play each other twice in the same season, it more likely that the same team will win both games (58%) than it is than a different team will win each game (42%). Why is this the case? One explanation is that in many matchups, one team is a lot better than the other team (e.g. the Tom Brady led Patriots against, well, anyone in their division). This team will usually win both games, even though they have to get one road win to do so.

Bonus: How Often Does the Home Team Win Each Game?

Because team plays one home and one away game, when a different team wins each game, one of two things has happened. Either both teams won their home game, or both teams won their away game. How often does the home team win both games?

Across all the cases where a different team won each game, the home team won both games 61% of the time. This may seem low, as it means that 39% of the time, both teams win their away game. However, if we look at all regular season NFL games in the same time period, the home team won only 55% of the time.

Thus, in cases where a different team won each game, the probability that the home team won each game (61%) is higher than the probability of a home team winning a regular game (55%). This makes sense. After all, we are looking at instances where one team won each game, meaning that the teams should be relatively evenly matched. It seems logical that home field advantage would be larger when teams are otherwise equally in strength.