S.L. Benfica 2015, Benfica reported to have 246,401 members; however, after a scheduled renumbering by the club in August 2015, the number decreased to 156,916. In April 2017, Benfica reported they had a total of 184,264 members by 31 December 2016. Benfica has rivalries with Sporting CP and FC Porto, with whom it forms the "Big Three": Portugal's most decorated clubs. None of them have been relegated from the Portuguese league since its establishment in 1934. As Lisbon-based clubs, Benfica and Sporting have shared a rivalry for over a century; it all started in 1907 when eight prominent Benfica players defected to
1985–86 S.L. Benfica season match with Salgueiros, which had been postponed in February because of the pitch conditions. They drew 1–1 and lost points in title race. In April, Benfica received Sporting in what was labelled the D-Day for the league. Despite leading the league for most of second round, they lost 2–1, which allowed Porto to catch them in the first place, with a better head-to-head record. Mortimore said: "Sporting had two chances and converted them both, we had lost the league". On the last day of the campaign, Porto beat last classified, Sporting da Covilhã and won the league, while Benfica lost