NBA challenge rules: Explaining how coaches can trigger instant replay review

Kyle Irving

NBA challenge rules: Explaining how coaches can trigger instant replay review image

The coach's challenge is relatively new to the NBA, and the league already has altered the process slightly since its debut.

You know when a controversial call happens and every person on the court starts wagging their pointer finger in a circular motion for a review? As of 2019-20, coaches can call a timeout and request a challenge on the floor.

The procedure started as a trial run. After it was met with resounding approval, the NBA elected to keep the coach's challenge for good heading into the 2020-21 season.

Ahead of the 2023-24 season, though, the NBA made changes to the number of challenges and how it affects timeouts. The Sporting News breaks down the coach's challenge rules below.

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How the NBA coach's challenge works

(Per the NBA's official 2023-24 rulebook)

  • Each team is entitled to one challenge to start the game. If that first challenge is successful, coaches will be rewarded with a second one, as of the 2023-24 season.
  • Coaches cannot challenge a call in the final two minutes of the fourth quarter and last two minutes of any overtime. During those minutes, only officials can trigger a review.
  • A team may utilize a challenge to trigger instant replay review of only the following three events:
    • (1) a called personal foul charged to its own team
    • (2) a called out-of-bounds violation
    • (3) a called goaltending or basket interference violation
    •  Any called foul, violation, or other decision by the game officials not listed above, or any non-call, is not a challengeable event.
  • The on-court crew chief makes the final decisions on foul call reviews. The replay center referee makes the final decisions on all other reviews.
  • Here is the wording that matters most on challenges: "Clear and conclusive visual evidence" is required in order to overturn a call on the floor.

How NBA coach's challenges affect timeouts

A coach must call a timeout to signal for a challenge on the floor.

  • If the challenged call is not overturned and the challenge is deemed unsuccessful, the challenging team loses its timeout.
  • If the challenged call is overturned and the challenge is deemed successful, the challenging team retains its timeout.

Kyle Irving

Kyle Irving Photo

You read that wrong – not Kyrie Irving. From Boston, graduated from the University of New Hampshire. Sixth season as a content producer for NBA.com's Global editions. Covering the NBA Draft has become his annual "dream come true" moment on the job. Irving has a soft spot for pass-first point guards, with Rajon Rondo and Steve Nash being two of his favorite players of all time.