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.
Bills–Patriots rivalry
In the 1990 season, the Bills reached the Super Bowl for the first time, playing against the New York Giants in Super Bowl XXV. Although obviously not a game in the rivalry, the 1990 Giants were coached by Bill Parcells (who had been linebackers coach with the Patriots in 1980) and defensive coordinator Bill Belichick; both would become head coach of the Patriots. The Giants won 20–19.