Because of the high number of teams participating in the league and eventual disagreements among the clubs, there were two separate groups in that year.
As a result, there were two Istanbul champions at the end of the season.
Galatasaray won the Istanbul Football Union League (Turkish: İstanbul Futbol Birliği Ligi), while Fenerbahçe became champions in the Istanbul Championship League (Turkish: İstanbul Şampiyonluğu Ligi).
[1][2][3][4] According to most sources, including RSSSF, there was a final match between Fenerbahçe and Galatasaray on 11 February 1916, which Fenerbahçe won 3–1, and thus became the sole champions of the 1914–15 season.
A playoff match was played to determine the winning team in the Istanbul Football Union League.