
This season, the NBA installed a challenge system. Each head coach can dispute one call per game. The new rule is on a one-season trial run—like a streaming service you’ll forget to cancel after 14 days—after being tested in the G League for two years. I loved the initiative from the very beginning, when I learned that the coach must “twirl his/her index finger toward the referees,” according to a memo the league sent teams. Twirl. I’m partial to anything that serves as a reminder that this is a sport, and that sports are silly. For good measure, there’s also a giant green light on the scorer’s table that blinks when a coach is calling for a challenge. Just in case he can’t twirl hard enough.

Not everyone shares my adoration for the new rule. There’s ill will toward sports reviews in general. Say “VAR” in public. Or ask DeAndre Hopkins how effective he finds pass interference challenges. Reviews are one of those few things so universally despised that we can bond over our shared hostility toward them. Yet the intentions behind every added review rule are good. In theory, the game will be more fair, and the rules process more transparent. There will be less human error. Fewer complaints. Maybe even a decline in referee death threats.
But some coaches are already quite displeased with the experiment. Earlier this week, after winning a challenge, Celtics coach Brad Stevens was caught on camera appearing to say, “I’m done with these fucking challenges. This is unbelievable.”
I’ll get back to Stevens’s profane dissatisfaction in a moment. First let’s go over the details of the challenge rule. Coaches can challenge three different types of plays: a personal foul called on their team, an out-of-bounds call, or a goaltending/basket interference call. To challenge, the coach has to call a timeout during the dead ball, then twirl his little heart out. If the challenge is successful, the coach gets his timeout back. If not, he loses the timeout. Each coach gets one challenge per game.
Coaches are apprehensive of the new rule two months in, despite having collectively challenged 184 calls (as of December 3). It’s an additional, perhaps unwanted spotlight for decision-making. In October, after two failed attempts, Raptors coach Nick Nurse said, “I don’t have any idea what I’m doing there. Zero.” Though Nurse was the first to try a challenge, it took seven tries before one worked out for him.
Nurse has challenged 10 total calls this season; two were successfully overturned. His attempts, like he suggested, have below league average returns. Overall, 45 percent of challenges have resulted in overturned calls. That breaks down to 41 percent of foul calls being overturned, 71 percent of out-of-bounds calls, and 57 percent of goaltending calls. That’s no insignificant rate, especially for a league with the most parity it’s had in years. Statistically speaking, the coaches challenge looks like a success. It’s unfamiliar, and it’s human nature to fear the unfamiliar, but it’s also human nature to fuck up a big foul call in the fourth quarter. Which is scarier?
The loudest concern is that challenges slow the game down. Fans, broadcast crews, anti–James Harden activists, and the league all agree that “slowing the game down” makes for a worse product, but for coaches, it’s a matter of momentum. Steve Kerr has said he’s “not a big fan” of the new rule because of the additional stoppages.
“I’m not a fan of replay in general,” Kerr said in November. “There’s way too many stoppages in play already. … I think we’re trying for the impossible and I think the flow of the game is much more important. Maintaining the flow and the consistency and the speed of the game is much more important than trying to be perfect on every play.”
Kerr’s point is valid, even if it reads like a setup for an “OK boomer” response. Dead time does pile up. Yet he’s already challenged 11 calls this season and is voluntarily utilizing the tool he is vocally opposed to, because ignoring it would put him at a disadvantage. It’s a microcosm of how the best coaches survive: evolving past each other schematically, and countering new systems with new systems of their own. Challenges are another strategic element to master. Kerr might not love it, but he’s a head coach. He has to take advantage of everything available to him.
A couple of times this season, the successful challenges have been unfulfilling. In Stevens’s case, he challenged a foul called on Grant Williams, which resulted in an and-1 for Julius Randle. After the play was reviewed, refs overturned the call, but with a catch: Randle was already shooting, so his basket was considered good. Another unintended consequence during foul challenges is getting the call overturned only because the officials realized it was another player on the team who fouled. A coach could inadvertently get his own guy into foul trouble trying to bail out another. (This has also happened to poor Stevens, against the Kings in November: He challenged a foul call on Enes Kanter, which was overturned and assigned to Brad Wanamaker, instead.)
The biggest disadvantage is that the opposition may always use a challenge. There are plenty of egregious, game-altering calls that teams get away with in a season. A coach’s opinion of the new rule will likely flip by the game. In November, Doc Rivers unsuccessfully challenged a foul call against the Bucks. After the game he said, “They should’ve overturned it. That’s why I hate the rule. Nobody wants to be wrong. Let me just say that.” (NFL receivers could not agree more.) Then, less than two weeks later, Rivers changed his mind after winning a challenge against Oklahoma City with 7.3 seconds left in the fourth quarter. “I’m changing my opinion,” he said after the game, which the Clippers won. “I think the challenge is good for the league, after all.”
The French author Antoine de Saint-Exupéry wrote that “Only the unknown frightens men. But once a man has faced the unknown, that terror becomes the known.” I’m completely sure he was talking about review calls in sports. Imagine when this all clicks for a coach like Stevens, who is rarely stumped, and he has another advantage. Terror.