The NBA is implementing a pilot program this summer which will allow coaches to make challenges during Summer League play and will use the new rule during the 2019-2020 regular season, according to ESPN’s Zach Lowe.
The program will see coaches get one challenge per game, which they will lose even if the challenge proves to be successful, and they can use it to challenge only called fouls, goaltending, basket interference and plays.
The league has tested this version of the challenge system in their developmental league, the G League, over the past two seasons.
Per the rule, in order to use the challenge, coaches must have a timeout remaining and the team must call a timeout immediately after the event that it would like to challenge, and the coach looking to make the challenge must “twirl his/her index finger toward the referees” to signal for the challenge.
If the challenge is successful, they keep the timeout they used to make it, if it is not, they lose the timeout.
The crew chief of the referee crew will be tasked with determining the outcome of the challenges involving called fouls, and the NBA Replay Center will decide all other challenges.
For technical and flagrant fouls occurring during or immediately after the call being challenge will stand regardless of the outcome of the challenge.
The NBA issued a memo to teams outlining the details on Friday.