Watch: Sam Hauser beats the buzzer for point differential

Even though the Atlanta Hawks clinched the top spot in the East’s Group C by beating the Cleveland Cavaliers, the East’s wild-card spot is still open. That slot will go to the team that goes 3-1, doesn’t win their group and has the best point differential.

That means the Celtics had a huge incentive to run up the score in their 138-129 victory over the Chicago Bulls. The aggressiveness worked for and against them. Jrue Holiday effectively clinched the game by tipping in a Jaylen Brown miss to give Boston a seven-point lead, but the point differential element made the Celtics play unusually aggressive.

Al Horford fouled Coby White on a three-point attempt with 14 seconds left to give him three free throws and potentially make the Celtics’ margin of victory dangerously slim. That’s why coach Joe Mazzulla called timeout with one second left to set up Hauser’s shot.

The buzzer-beater gave Boston a +23 differential in Cup play. With Atlanta winning the group, the Celtics have a small edge on their wild-card competition.

The Milwaukee Bucks (+29) and Detroit Pistons (+23) face off Tuesday to see who wins Group B, so Boston would love a Bucks win. The Orlando Magic (+60) face off with the New York Knicks (+15) for first place in Group A, so the Celtics need a Magic win or at least a close loss to punch their ticket to the knockout round.

This season, teams seem aware of the point-differential tiebreaker, so players aren’t as upset as they normally might be. Last season, the Celtics worked hard to run up the score on the Bulls in their final in-season tournament game, even intentionally fouling Andre Drummond to get a better differential in their 124-97 win. Afterward, Mazzulla apologized to Drummond.

It’s a weird element of the NBA season, but it does provide some extra excitement. For at least four games a year, fans can get hyped about a buzzer-beater that doesn’t affect the outcome of the game at all. That’s strange, but if it makes fans care about garbage time in a November game, the NBA is all for it.