The Celtics have made it clear all season long: they care about the NBA Cup. Sure, it’s not the playoffs, but it’s still something they can win in the regular season. Since the C’s were fighting late against the Bulls for a place in the knockout rounds, they played until last Friday in Chicago for points difference reasons.

Although the Celtics were already six points ahead of the Bulls with just seconds left, they called a timeout with 1.4 seconds left. This allowed them to advance the ball and gain another possession to maintain the point differential. In the end, they secured the nine-point victory over the Bulls with a 3-pointer from Sam Hauser. And C’s coach Joe Mazzulla said after the game that he enjoyed that rules aspect of the NBA Cup.

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“I like it because this tournament and the point differential kind of overrides the unwritten rules that you should follow or not follow,” Mazzulla said after the game, via NBC Sports Boston. “In a normal situation you wouldn’t do that. But in this case, you can design a piece and try to get better in this situation. So the boys did a good job and we tried to increase the points difference as much as possible.”

It’s the second straight season the Celtics have needed to surpass the Bulls. The C’s had to win by at least 23 points last season, which they did by reaching the knockout rounds of the NBA Cup. This year, the C’s needed to increase their point differential as much as possible after the Hawks beat the Cavaliers the previous Friday.

Atlanta’s win means that Boston’s only place in the knockout round of the NBA Cup, which includes the best runners-up from the three East groups, is via a wild card. So in the tiebreaker it comes down to the difference in points. Here’s a look at what exactly the Celtics need to do on Tuesday to ensure they can reach the quarterfinals of the tournament.

The league introduced the in-season tournament last year and added some new elements to the regular season. Not only are the games more competitive on these eye-catching pitches, but the difference in points often doesn’t matter in the league. Now some of these games have a little more pizzazz, and some people will enjoy that.

“It’s different,” Mazzulla said. “I think they enjoy it. It adds a little life to the regular season game. I know Sam likes it any time he gets a chance.”