Complex sentence: The reserve team entered the Great Western Suburban League for the 1905--06 season and finished as champions in 1907--08,1908--09 and 1910--11 and runners up in 1905--06,1906--07 and 1909--10.
Split into simpler sentences: The reserve team entered the Great Western Suburban League for the 1905--06 season and finished runners-up for two seasons in succession. The reserves were champions in 1907--08,1908--09 and 1910--11 and runners up in 1905--06,1906--07 and 1909--10.