American football rules
Super Bowl LI was the first Super Bowl to go into overtime with a 28-all tie between the Atlanta Falcons and New England Patriots, which the Patriots eventually won with James White scoring a touchdown on the Patriots' first drive.
New England Patriots
The Patriots first played the Miami Dolphins in 1966 in the AFL, when Miami was one of two expansion teams to debut that year in that league. The Dolphins dominated the Patriots in the 1970s and 1990s, but the two teams remained competitive with each other for years before the rise of Tom Brady. Brady, however, struggled occasionally against the Dolphins in the 2000s before reasserting dominance in the 2010s. The Patriots and Dolphins are the only two teams in the Super Bowl era to post undefeated regular season records, with Miami going 14-0 in 1972 and the Patriots going 16-0 in 2007. Notable moments between the clubs include the Snowplow Game, three playoff matchups, and the Dolphins revealing their Wildcat offense against the Patriots.