The NBA will be experimenting with adding a coach’s challenge to its current replay review system. The trial will begin with summer league basketball next month, but the league “anticipates using the rule during the 2019-20 regular season as part of a pilot program,” according to Zach Lowe of ESPN.
The G-League has had a challenge system implemented for a couple of years, and the NBA feels comfortable enough about it to try it out on the big stage.
“Coaches will get only one challenge per game, whether it is successful or unsuccessful, according to the memo. They can use it to challenge only called fouls, goaltending, basket interference and plays when the ball is knocked out of bounds, the memo says.
Coaches must have a timeout remaining to use a challenge. The team must call a timeout immediately after the event it would like to challenge, and the coach must “twirl his/her index finger toward the referees” to signal for the challenge, the memo states. If the challenge is successful, the team retains the timeout it used to stop play. If the challenge is unsuccessful, it loses that timeout.”
This should get really interesting.