Can Joe Mazzulla Basketball Get Jayson Tatum and Celtics a Championship?

Joe Mazzulla loves math. Throughout the first half of the season he’d throw expected shooting stats, points per possession, rim read percentage, a data point I’d never heard of prior, and different lineup data, always with a focus on the three-pointer. The Celtics could always shoot more threes.

Jayson Tatum got to watch Mazzulla ball from the broadcast vantage point when Boston visited Milwaukee without him on Tuesday. Tatum stayed home with a real non-COVID illness before unloading the easiest 38 points of his career on the Pistons the next night in that system, shooting 15-for-24 and hitting six threes. Tatum finished the first half of the season with 30.6 points, 8.6 rebounds and 4.5 assists per game on 46.4% shooting, the best marks of his career after a rough postseason where defensive pressure overwhelmed him.

“I joked about it, we shoot a lot of threes,” Tatum said on Wednesday. “I noticed that yesterday. We shoot a lot of threes, but guys were knocking them down, and we had a chance to win the game … all things considered, everything that we went through this season as a team with coaching changes and guys getting injured and missing games and being in and out of the lineup … overall, it’s been a hell of a start.”

The start placed Tatum in MVP contention and impressed the Celtics enough to name Mazzulla head coach and extend him long-term on Thursday. Tatum lauded Mazzulla as early as last June during the Finals and committed to the principles he emphasized upon becoming the interim coach last fall, however unnatural for the team. After receiving some of the most double teams in the league one year ago, Tatum no longer ranks in the top-20 per game.

Three-point volume defined the Celtics during the first half of the season. They shot 40% as a team through a 21-5 start and boasted the most efficient offense ever. That slid as the shots stopped falling through the actual halfway point of the season and recovered as Boston won 7-of-10 into the break. The Celtics hit 16 threes or more in each of their last six games, increasing their attempts to at least 45 for the final four after attempting fewer than 40 in the three games prior. The team currently ranks six all-time with 42.2 three-point attempts per game.

They have the personnel to justify it and doubled down by adding Mike Muscala at the trade deadline, a 39.4% shooter from deep this season who averaged 7.7 attempts in his first three games with Boston. Muscala lauded the Celtics staff allowing players to play with freedom, but Boston didn’t simply launch threes in the first half of the season. They created them methodically with a 63.1 AST% that ranked fifth in the NBA and 83% of their threes came from assists (14th). The Celtics assisted 66.7% of Tatum’s three-point makes, compared to 56.5% in 2022. Most impressively, all that spacing allowed Tatum and Jaylen Brown to both shoot 70% in the restricted area.

Mazzulla always worked to reset Boston’s spacing and while he stepped in to readjust the series of play calls at the Celtics’ disposal on the floor, he typically left those calls to the players. He relented to that approach on Tuesday, when he admitted he should’ve called timeout to set up a final-minute play with Boston trailing by three points in Milwaukee. His timeout frequency increased in recent weeks after he expressed a desire to change that approach.

“As the season goes on, you’re looking to learn,” he said this month. “As a team, you have to do different things. At the beginning of the year, I felt like we needed a mindset of organization and understanding what’s going on. I still think in some of those moments, that’s necessary, but I think the game presents opportunities where you need them … I called one with 1:15 left in (overtime against the Lakers) just to get a lineup in because we were winning and if we could get a basket, it’d be a two possession game.”

Tatum scored two early baskets sprinting ahead of the Pistons on Wednesday to catch feeds from Derrick White and Marcus Smart. He screened-and-rolled to score on a pass from Smart nearly uncontested. Later, they combined on the same play and Tatum concluded his night by driving, firing a pass to Grant Williams, repositioning himself in the dunker’s spot and catching a Malcolm Brogdon pass on the drive for his final finish. That approach differed almost completely from the plodding pace he played at last season.

Mazzulla altered Brown’s role too, embracing his mid-ranger and utilizing him as a screening and finishing player on offense. He shot 48.7%, a career high, as he focused on playing closer to the basket and catching passes to make additional ones or finish in traffic. It made him an all-star after a year away from the showcase and put him on pace for All-NBA status and an inevitable super max extension. That could mark Mazzulla’s long-term legacy. In the short term, he helped Sam Hauser escape a two month slump by integrating him into the starting lineup.

“I think our early offense creativity, our early offense unpredictability allowed for more of that, especially early in the shot clock,” Mazzulla said. “We’ve got to do a better job of recognizing the cross matches, getting into a quick trigger in the first 6-8 seconds, which will allow that unpredictability and open shots, which is something that really helped him. When shots started to fall, yes, I think that affected other areas of his game and I think a huge area of growth in his last couple of games, that wasn’t affected … value doesn’t come from their shot-making.”

The lingering question with Mazzulla pertains to how he handles the small sample size, compared to the larger resumé he built through a 42-17 start. The Celtics rank third in offense (116.9 points per 100 possessions) despite their midseason slump. The quick threes helped bolster their second-ranked assist-to-turnover ratio (1.96).

Their overall time per touch (3.18) could improve, but still approaches last year’s progress (3.07) as the Celtics start to more closely reflect recent Warriors and Jazz teams Brad Stevens looked up to. Mazzulla’s Celtics always fight their worst habits, particularly the temptation to attack one-on-one while hunting mismatches.

Then, the recent history of teams shooting their volume of threes raises some concern. The 2018-19 Rockets, who shot the most threes per game ever, fell in six games to the Warriors in the second round. Their 2020 team shot nearly as many and lost to the Lakers in five games, despite hitting 36% from three in each postseason. The 2021 Jazz fell in six to the Clippers and the 2023 Warriors won the title.

The 2018 Rockets might have won the title if not for Chris Paul’s injury, but they also fell with a 3-2 series lead to Golden State following their infamous 0-for-27 three-point drought. The Celtics play better defense than those Rockets teams, don’t face the Rudy Gobert limitation Utah did and have the heliocentric player like Curry to create those quality shots. They’ll need outlets if they go cold in the spring.

Whatever role Mazzulla played in his transformation, Tatum’s new game shares some of the activity Curry plays with off-ball. He reminds the Celtics to stick to those habits often, almost knowing they can slip at any moment. Boston’s fate won’t be decided by his coaching, but he’ll need to hold the players to the strides they’ve made after offense cost them a championship.

More than all that, Stevens believed in Mazzulla’s ability to connect with Boston’s players, taking the opposite approach of Ime Udoka in addressing them publicly. He’s called numerous losses great for their approach, kept injuries and internal matters close to the vest, and stressed lending an ear through turbulent moments like camp.

“I think Jayson learns from great players in general,” Mazzulla said. “He’s always trying to find ways to gain an advantage, and so I think he’s done a great job learning from the Finals, learning from every experience he’s had about how he can get better. So attacking the rim, screening, spacing, catch-and-shoot threes, it kind of all goes into his work ethic toward getting better.”