Jaylen Brown’s efficient shooting and other observations from the Celtics’ Game 3 victory

The Celtics led by 23 points in the third quarter before the Cavaliers rallied. Cleveland pulled within 9 three times.

Donovan Mitchell had 33 points to lead the Cavaliers. He made 7 of 12 from 3-point range, but the rest of the team made 5 of 24.

Game Observations:

▪ Playing Al Horford at center rather than the injured Kristaps Porzingis allows the Celtics to switch positions at every position, but it doesn’t always end well. Three times in the first half, Mitchell shook the 37-year-old big man from beyond the arc and scored three points. To be fair to Horford, the Celtics’ other defenders didn’t fare much better in the first half. Mitchell made 8 of 12 shots and 6 of 8 3-pointers, for a game-high 23 points.

Horford also missed his first five 3-pointers and played nearly 40 minutes, a heavy workload that could affect his offense.

▪ The problem for Cleveland in the first half was that Mitchell had little help. The other Cavaliers combined to go 2 for 15 from the 3-point line. Dean Wade, who had been sidelined with a sprained knee since March 8, entered the game with four minutes left in the first quarter and scored three points shortly after. But he missed his other two attempts.

▪ Tatum started the game like he was bothered by talk of his lukewarm start to the playoffs. He gained confidence by hitting two early 3-pointers and went after his shot as aggressively as he has in weeks. His approach was remarkable because it was varied. He didn’t just make 3-pointers or lower his head to try to commit fouls. There was more creativity. He calmed down a bit but arrived at halftime with 18 points on 6-for-12 shooting.

▪ Tatum’s outburst was big, but it also contributed to the Celtics outscoring the Cavaliers by 7 points during his lengthy stint on the bench in the first half.

▪ Jrue Holiday clearly emerged as the fifth offensive option among Boston’s starters during the regular season, primarily settling into his role as a blocking defender and finding transition opportunities. But in the first half he showed unusual aggression and urgency. Maybe the only NBA champion on the roster realized that was what this team needed during this rare moment of slight discomfort.

On several possessions, he backed his defender into the paint and converted a sweet left hook, sometimes even on the long and talented Evan Mobley. One sequence was particularly noisy. After scoring inside, Holiday grabbed an offensive rebound on Boston’s ensuing possession and found Sam Hauser for a 3-pointer. Then, on the other end, he stripped Caris LeVert and knocked the ball off his leg. Holiday had 15 points in the first half. He last reached that total in an entire game on March 12 against the Suns.

▪ Celtics coach Joe Mazzulla has a few game situations he hammers home long after the Celtics are tired of hearing about them. Here’s one: Every time an opponent goes down after making a layup, the Celtics should run, run, and run some more, taking advantage of the rare power play. They’ve generally done a great job this year, and on one play in the first quarter, LeVert fell to the floor after a layup. Tatum noticed, and two quick passes later, the Celtics got a layup.

▪ The start of the third quarter was almost perfect for Boston. On the first two possessions, Tatum converted a 3-point play and White made a 3-pointer. If this simple sequence had been reversed, it would have been a 3-point play. Instead, it was the start of a 14-0 run that was capped by a Holiday three-pointer that gave the Celtics a 71-48 lead, their largest. However, they couldn’t really deliver the finishing blow at this point. The Cavaliers responded with a 9-0 run that kept them within striking distance for the rest of the quarter.

▪ The Cavaliers, already without starting center Jarrett Allen, got a scare when Mobley limped in after an awkward touchdown early in the third quarter. He limped to the bench and received medical attention, but returned late in the period and gave the Cavaliers a boost early in the fourth, scoring two inside baskets during a flurry of 6-0 which brought the score to 84-75. The Cavaliers struggled with their shooting, but persisted in part because after committing six turnovers in the first quarter, they had just two over the next two quarters.

▪ As his team struggled to find offense, Cleveland coach JB Bickerstaff looked everywhere for a spark. For a long stretch in the second half, he placed a four-guard formation around Mobley. Although the speed gave the Celtics problems, they overpowered the Cavaliers on the other end.

Adam Himmelsbach can be contacted at adam.himmelsbach@globe.com. follow him @adamhimmelsbach.