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
1986–87 S.L. Benfica season campaign started with a Clássico with Porto, which ended with a draw. A win in match-day 2 was followed by another draw. Six consecutive wins propelled Benfica into first place isolated, with two points in hand. In the end of November, Benfica contested the Supertaça with Porto and was defeated by 4–2 at home, after a one-all draw in Antas. On the second week of December, in the Derby de Lisboa with Sporting, Benfica conceded their largest loss ever in the Primeira Divisão, losing 7–1. Fans reacted with anger towards Mortimore and ripped flags and scarfs with the club image.