American Basketball Association (ABA), former professional basketball league formed in the United States in 1967 to rival the older National Basketball Association (NBA).
The ABA fielded 11 teams in its first season and quickly earned a loyal following with its wide-open style of play. The league introduced a number of rule changes, most notably the three-point shot and a red, white, and blue ball. The quality of play was equal to that of the NBA, and the ABA nurtured the careers of Julius (“Dr. J”) Erving, Connie Hawkins, and David Thompson.