The Donovan Index

The Leagues used to calculate the Donovan Index either are currently preeminent (NFL, MLB, NBA, NHL), merged into a preeminent league (AAFC, AFL, ABA, NHA, WHA), or rivaled a preeminent league (PCHA, WCHL). Championship credit is awarded for:

Football

NFL champions 1920 to present (must have won Super Bowl after 1965)
AAFC champions 1946 to 1949
AFL champions 1960 to 1969 (must have won Super Bowl after 1965)

Baseball

MLB champions 1903 to present, minus 1904 and 1994

Basketball

NBA champions 1946-47 to present
ABA champions 1967-68 to 1975-76

Hockey

NHA Stanley Cup champions 1909-10 to 1916-17
PCHA Stanley Cup champions 1911-12 to 1923-24, minus 1918-19
WCHL Stanley Cup champions 1921-22 to 1925-26
NHL Stanley Cup champions 1917-18 to present, minus 1918-19 and 2004-05
WHA champions 1972-73 to 1978-79