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
1974–75 S.L. Benfica season first but drew the others. First with Sporting on the 22, for the Derby de Lisboa, and then on the 29, with União de Tomar. Benfica lapped the first half of the season in second place with three points less than leaders Porto. In January, Benfica won their opening match, while Porto lost theirs, reducing the gap between them to a point. Two weeks later, Benfica defeated Olhanense on the road and Porto lost in Alvalade, with the teams exchanging places. Benfica now led by a point over Porto. In the last match of the month, Benfica defeated Leixões at