4.5 drinks

According to the study by alcohol.org, [New Orleans] Saints' fans drink an average of four-and-a-half drinks per day on game day. Those same fans consume three drinks per day on non-game days. On the other end of the spectrum, fans of the Indianapolis Colts are the most sober fans in the league. Oddly, Colts' fans drink more on non-game days (2.5) than game days (2).

Source: Nola.com