Coach's Challenges Are Coming: Is the NBA Ready?

The NBA is adding coach's challenges on a trial basis for the 2019-20 season. As Summer League in Las Vegas is showing, the process is still very new for everyone involved.

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LAS VEGAS — Jaxson Hayes skied toward the rafters, his interminable left leg functioning more like a pogo stick. As the Pelicans’ rookie center soared higher and higher, his right knee collided with poor, 6’4” Mychal Mulder’s throat. The Chicago Bulls' guard here at Summer League crashed to the hardwood. Hayes viciously tomahawked the unquestioned highlight of this year’s July event. 

Hayes dapped multiple players sitting along the baseline. Both benches erupted. The Thomas & Mack center momentarily recaptured the electricity from Friday night’s earth-rattling debut of Zion Willliamson. Only then the arena’s public address announcer revealed Bulls Summer League head coach Nate Loenser was challenging the foul. “I was like, what are they challenging?” Hayes told SI.com. “He slid in late, it’s definitely not a charge.” 

The NBA first tested a coach’s challenge during the 2018 Las Vegas Summer League, and after being implemented in the G League the past two seasons, plus another trial run during this week’s games, the Board of Governors voted on Tuesday to bring the program to the NBA on a one-year trial basis during the 2019-20 season. Each coaching staff will hold one challenge per game—regardless of whether the rebuttal is successful—with the option to trigger reviews for called personal fouls charged to their own team; a called out-of-bounds violation; or a called goaltending or basket interference violation. 

A team can use its challenge on a called personal foul at any point in the game. But in the last two minutes of the fourth quarter or the last two minutes of overtime, out-of-bounds and goaltending calls will not be challengeable. Those situations are only reviewable by the on-court referees. To issue a challenge, teams must immediately call a timeout and the head coach must sequentially twirl a finger toward the referees. In congruence with typical replay reviews, conclusive visual evidence is required to overturn a call on the floor. 

Milwaukee challenged a whistled foul late in the Bucks’ Friday afternoon 107-106 loss to Philadelphia. Milwaukee’s staff thought a critical scrum in the paint appeared to have led to a clean strip of the ball. Bucks assistant Josh Longstaff served as the Erie Bayhawks’ head coach during 2017-18. Harboring a familiarity with the challenge, Longstaff advised Milwaukee’s Summer League head coach Darvin Ham to twirl his finger and trigger the appeal. The Bucks’ protest failed, however, costing Milwaukee an important timeout in an eventual single-point defeat. “You better be sure, because it will cost you,” Ham said. “Later on in the game, it came down to where we definitely could have used a timeout.” 

Sixers Summer League head coach Connor Johnson, who led the Delaware 87ers this past season, debated challenging a foul on a three-pointer late in the fourth. “That’s a pretty big play: three points with a two and a half minutes left. Do we challenge that?” Johnson said. “I don’t think anyone’s really figured out the science of that yet and we will as we go.” G League coaches have typically holstered challenges for critical fourth–quarter whistles. Oklahoma City Summer League head coach David Bliss opted against challenging an out-of-bounds call in the Thunder’s Monday afternoon bout with Johnson’s Sixers. “I wanted to save the challenge in case I needed it late in the game,” Bliss said. “It’s always one of those kinda Catch-22s. It’s like, I’m pretty confident that we could get that play, but how much does that change the game?”

The ability to challenge fouls had been a controversial development amongst league personnel discussing the 2019-20 trial. Coaches and fans alike have long recognized whistles favor star players versus supplementary glue guys and rookies. Beaming a microscope on such an inconsistent judgement could ultimately prove suboptimal for the NBA, just as the league’s last two minute reports have sparked mixed reviews on that level of transparency. And there are still many wrinkles to iron out within the challenge’s guidelines as well. 

“In some situations, you have to draw up two different plays depending on the outcome,” said Steve Gansey, Indiana’s Summer League head coach who has piloted the Fort Wayne Mad Ants since 2015. “The ball could be out of bounds or in a different spot or even be ruled a jump ball. I wish they would give you 30 seconds after the outcome to draw something up when you know the exact situation.” Gansey also suggested allowing coaches to challenge calls in the final two minutes. Objectively, it would make sense for a staff’s one attempt to overrule an official to be accessible during a game’s most-scrutinized moments. 

Another touch point: the immediacy of the challenge was not an element in this Summer League’s test run, or at least it wasn’t enforced. The Nets’ staff believed a called blocking foul actually should have been deemed a charge, but polled their players before signaling for a challenge. Theo Pinson was adamant the defender’s feet was set, and so Brooklyn’s Summer League head coach Adam Harrington twirled his finger. “I told Theo that he’d owe me dinner if we lost it,” Harrington said. Pinson did not have to relinquish any of his per diem. 

The NBA’s general experimentation with video replay, just like the coach’s challenge, is still in its infancy. A new “courtside administrator” will be stationed at each arena’s scorer’s table to expedite communication between the NBA Replay Center and the game’s officials, for example. In this era of efficiency, the league is determined to accelerate the speed of its in-game reviews. How the coach’s challenge impacts the overall stoppage time due to replay may be one of the deciding factors on the rule’s future beyond 2020. For now, coaches’ ability to call for a replay review… will remain under review itself.