The Leagues covered by the Donovan Index include the currently preeminent leagues in the four major sports along with defunct leagues that either merged with or rivaled a preeminent league.
Football
- NFL 1920 to present (must have won Super Bowl after 1965 to be considered champion)
- AAFC 1946 to 1949
- AFL 1960 to 1969 (must have won Super Bowl after 1965 to be considered champion)
Baseball
- NL 1876 to 1902, 1904
- AA 1882 to 1891
- AL 1901 to 1902, 1904
- MLB 1903 to present (minus 1904 and 1994 when no World Series)
Basketball
- NBL 1937 to 1949
- BAA 1946 to 1949
- NBA 1949 to present
- ABA 1967 to 1976
Hockey
- NHA 1909 to 1917
- PCHA 1911 to 1924 (minus 1919 when no Stanley Cup)
- NHL 1917 to present (minus 1919 and 2005 when no Stanley Cup)
- WCHL 1921 to 1926
- WHA 1972 to 1979