American Basketball Association
Years of Existence: 1967-1976
If you want to talk about innovation in sports, you have to start with the ABA. The three-point line, the slam dunk contest, and the spectacle that has become All-Star weekend originated with this professional basketball offshoot. If you want to talk about desperate gimmicks like the Winter Classic, the All-Star Game Draft, and executive compliance with in-game violence, stick with the NHL.