Coaches will be allowed to challenge one call per game

LAS VEGAS — NBA coaches who want to dispute calls can now do more than shout at officials. They can twirl a finger.

That would be a more effective response than the protests have been, with coaches now able to trigger a replay review, though they are limited to just one per game and only on certain calls.

“It’s a one-year experiment,” NBA commissioner Adam Silver said of the pilot program, approved as expected by the NBA Board of Governors on Wednesday. “It’s fairly limited. There were discussions with the competition committee whether it should be more expansive. We’re trying to balance the flow of the game and not create too much stoppage with trying to get our calls right.”

A coach may challenge personal fouls, out-of-bounds violations, and goaltending and basket interference violations if called on that coach’s team.

Coaches must immediately call timeout and signal for the challenge. Even if the challenge is successful, they don’t get another. Teams do not lose the timeout if the challenge is successful but must have a timeout remaining to challenge a call. Challenges of basket interference or goaltending and of out-of-bounds violations will not be permitted in the final two minutes of the game or last two minutes of overtime.

The NBA replay center also will be permitted to trigger a review of whether shots were 2- or 3pointers, as well as shot-clock violations. A liaison between the replay center and the officials will be stationed at the scorer’s table.