Complex sentence: The National Association of Professional Base Ball Players (1871-1875) did not schedule games, nor did it control the number of teams, a major reason for its demise after the 1875 season.
Split into simpler sentences: The National Association of Professional Base Ball Players (1871-1875) did not schedule games. Nor did it control the number of teams, a major reason for its demise after the 1875 season.