How do you measure a “rivalry”? Is it how much you hate someone? Is it how often you have competed head-to-head for an important goal? Is it how often you spend your time talking about someone? As in previous studies, we decided to use Twitter to quantify the level of rivalry between teams in the same division in the NFL. We are starting with the teams in the NFC West: The Seattle Seahawks, the San Francisco 49ers, the Arizona Cardinals, and the St. Louis Rams.
Our methodology is straightforward. We are measuring the intensity of a “rivalry” by the number of tweets mentioning a non-home team in the home team’s market. For example, we look at the number of tweets mentioning the 49ers, Cardinals, and Rams in the Seattle market. These tweets represent the relative intensity of rivalry of each team with the Seahawks fan base. We realize that a limitation of this method is that some of these tweets could be from 49ers, Cardinals, or Rams fans that live in Seattle. For each market, we index the tweets relative to the team with the most tweets (e.g. if the 49ers have the most tweets in the Seattle area, we divide the number of tweets for each team by the number of tweets that mention the 49ers). We perform this analysis for a four year period and for just the 2013 regular season, so we can capture established rivalries and the recent trend.
It is interesting to note that in both analyses, the 49ers and Seahawks are each other’s primary rival and the intensities of the secondary and tertiary rivalries are not even close. Over a four year period, the 49ers are the primary rivals for all of the teams in the NFC West, but in just the 2013 regular season analysis, the Seahawks took over as the primary rivals of the Cardinals, and are barely behind the 49ers in terms of the intensity of the Rams’ rivalries.
Mike Lewis & Manish Tripathi, Emory University 2014