The NBA announced two replay rule changes after its Board of Governors meeting at NBA Summer League: a coach’s challenge and expanded NBA Replay Center triggers. Two important features of the coach’s challenge are that 1. Coaches only get one challenge per game and 2. Challenges can only be used when “a called personal foul charged to [their] own team; a called out-of-bounds violation; or a called goaltending or basket interference violation.” To initiate a challenge, coaches must call timeout then “immediately signal for a challenge by twirling his/her finger toward the referees.”
The NBA Replay Center triggers include determining if a basket was worth two or three points (or if a player deserves two or three free throws on a shooting foul) and looking at if baskets were made prior to the shot clock expiring.