Agreements among the athletics departments in 1906, 1916, the "Three Presidents Agreement" on eligibility,[REF] and a revision of that Agreement in 1923 have been considered precursors to the Ivy Group Agreement creating the Ivy League, each agreement addressing amateurism and college football [REF].
Twenty eight different teams, 17 representing Harvard and 11 representing Princeton, have shared or won outright the Ivy League football title.