ØB was the smallest of the big five Copenhagen clubs, often losing their best players, such as later international Carl "Skoma'r" Hansen, to their rivals.
[4] Due to its consecutive poor performances in the Copenhagen championship, ØB was relegated to a newly created second-tier tournament, which the club duly won in 1908.
ØB won the second-tier tournament a number of times,[7] but failed to make a lasting impression in the Copenhagen championship.
ØB sought to strengthen the position and economy of the smaller Copenhagen clubs excluded from Stævnet, and was a co-founder of competing associations in the early 1920s, 1936, and 1940 (Alliancen).
[10] This ended ØB's long spell in the Copenhagen second-tier, as the 2nd Division took precedence as the highest-ranking full-season tournament for which the club was eligible.
[12] In the hope of economic gain and a long-term position among the great Copenhagen clubs, ØB decided to switch allegiance and join Stævnet in 1949.
Carl Aage Præst and Helge Bronee both left the club to sign professional contracts with foreign cubs, and ØB struggled without them.
[14] The club found itself competing in the fourth-tier Copenhagen Series or lower, and never rejoined the upper divisions of Danish football.