A December to remember?

The Celtics started December with a league-best 14-4 record and the NBA’s best net rating of 9.7 (116.9 offensive rating (9th), 107.1 defensive rating (2nd)). They’re undefeated at home (9-0) and per ESPN Stats, they’ve had the strongest schedule to date. After a nailbiter against the 76ers on Friday night, the rest of the month could prove to be a grueling gauntlet to Christmas Day.

This week is the conclusion of the league’s inaugural In-Season Tournament with the knockout round starting Monday in Indianapolis. The Celtics demolished the Pacers by 51 points a month ago, but Indiana was without Tyrese Haliburton and he’s the driving force behind the NBA’s most prolific offense. Tonight, the team will not have Kristaps Porzingis in the lineup as he recovers from a strained calf.

If Boston advances, they’ll face either the Milwaukee Bucks or New York Knicks in Vegas to determine the Eastern Conference rep in the NBA Cup final. The West bracket features the Lakers, Suns, Kings, and Pelicans.

Noticeably, the IST won’t feature either Finalist from last summer, two squads that would have tested Boston’s glaring weakness so far this season: bigger teams that can outmuscle them and get under their skin. However, their four-game homestand following the tourney will test their mettle. In a unique scheduling quirk, the Celtics will host the Magic and Cavaliers in back-to-back two-game mini-series.

After losses to the Timberwolves and 76ers, Orlando used those scripts to perfection in a 17-point beatdown last week. Last season, Cleveland won three of four of the regular season series that included three overtime losses punctuated by Grant Williams’ “I’ll make them both” game. The Cavs are just 10-9, but Donovan Mitchell is back and he’s always been a Celtics killer.

After a week of homecooking, the team will head out west with stops against all four California teams: a rematch of the 2022 NBA Finals against the Golden Warriors on Tuesday, the Kings on a back-to-back, Daniel Theis and his Clippers on Friday, and a Christmas Day rivalry and Game #373 vs. the Lakers.

Ten games — maybe eleven, fingers crossed. That’s eleven games that could go a long way in cementing this team’s identity as they head into the new year. Are they the defensive juggernaut that they’ve been all season? Will their offense eventually match their talent on the floor? Would a 5-5 split motivate President of Basketball Operations Brad Stevens to start combing the trade market? Would an 8-2 run that included solid play from Jaylen Brown and the Boston bench finally silence the haters?

Banner 18 won’t be hung in the rafters in December. Luke Kornet could pay off his mortgage if the team raises the NBA Cup on Saturday, but a championship...well, a championship is six months away.