Then the Celtics almost got another chance after Tyrese Haliburton missed a potential game-winning 3-pointer, but time ran out before they could call a timeout. Tatum scored 11 points in the fourth quarter, including seven in the final 1:28 of regulation, and had 37 points, eight rebounds, four assists and four steals. He also got to the free throw line 15 times.

However, Tatum was also 5 of 18 from 3-point range, giving him a mark of 13 of 44 (29.5 percent) since opening night. The sample size is obviously tiny (between his poor shooting against the Bucks and the Wizards was a solid night against the Pistons), but a better shooting performance from Tatum might have prevented the need for an extension.

2. The Celtics had a tough 3-point shooting night overall.

Tatum was far from the only player to struggle behind the arc.

Jaylen Brown was the biggest attacker – a disastrous 1-for-11 from deep as part of an 11-for-30 performance that included three turnovers that left much to be desired, even if he hit the penalty mark in other areas.

“Just the whole night, I just didn’t have any legs under me. No explosion. No explosion, and I think that’s what cost us,” Brown told reporters afterward.

Jrue Holiday was 1 for 3.

Sam Hauser was 1 of 4.

In fact, a real indicator of how cold the Celtics were was Payton Pritchard's 4-for-11 performance – a respectable 36.4 percent from deep, but well below his recent highs.

The Celtics can still win games by not making 3-point shots, but the margins are pretty close. A 19-for-57 shooting performance isn't the end of the world (33.3 percent), and 57 three-point attempts is a good indicator that the Celtics made a lot of good shots, but they need to win in a lot of other areas under these circumstances and before their late surge, the Pacers crushed them.

“I felt like we looked really good tonight,” Brown said. “We didn’t really shoot the ball. Our energy was just lackluster. A lot of it was up to me. I have to do better for my boys.”

3. Benedict Mathurin and Pascal Siakam punished the Celtics.

The Celtics appear to have a lot of answers for Tyrese Haliburton, but Benedict Mathurin tore them to shreds in both transition and half-court sets, going 9-for-17 en route to 30 points. Mathurin's finishing at the rim gave the Celtics fits, and once he found his rhythm, he made two of his five 3-point attempts.

Siakam wasn't quite as efficient (11 of 20), but he finished the game 6 of 8 from behind the arc, and his final three-pointer made the difference in overtime.

“I think Siakam shot the best ball I’ve ever seen, at least against us,” Brown said. “We normally guard him a little differently, but he shot the ball extremely well tonight. Last time we got the switch and maybe went a little too low. He was fine all night and managed to knock it down. Big hit.”

The Pacers are smart and can give up big leads as quickly as they built them, but they're not just a team with a difficult system to solve – they also have a lot of very good basketball players who can hurt you in many ways.

4. Derrick White is a big-game player.

Derrick White continued his (extremely) early push as the Celtics' potential third All-Star, scoring 23 points on 8-for-9 shooting and 5-for-5 from behind the arc. With the exception of a late foul that prevented the Celtics from forcing a crucial shot clock violation, White played a nearly flawless game and was one of the few players largely above criticism (more on the second coming off the bench). and had a huge impact within a minute).

White scored five of his points, including one of his 3-pointers, in overtime.

5. Transition defense is something to keep an eye on.

Before Wednesday's game, the Celtics were giving up 1.26 points per possession in transition, good for 29th in the league.

The Pacers outscored the Celtics 29-21 in transition and had the Celtics on their heels for most of the evening. The Celtics were also able to hold back the Pacers (Boston's transition offense is third in the NBA at 1.27 points per possession and has not caught on in the flood so far), but fast, chaotic teams like the Pacers have a chance plus the Celtics hurt as they hit a fast break.

“Credit to Indiana, I thought their speed, their tempo, they were a step ahead of us,” Joe Mazzulla said.

Again, the sample size is tiny, but the results are worth seeing.

6. Neemias Queta changed the game.

Trailing by 21 with 8:54 left, the Celtics substituted Xavier Tillman, Jordan Walsh and Neemias Queta. While these moves didn't quite wave the white flag, they did show they were thinking about it.

However, Queta had other plans. The big man immediately threw down an alley-oop dunk, then started gobbling up rebounds and flying around the floor. He recorded a big block and even assisted on a layup by Pritchard. In 13 minutes, Queta finished the game with nine rebounds and was +18 in a game the Celtics lost by three points.

7. Jaylen Brown gained eight pounds of muscle.

According to the ESPN broadcast, Brown gained eight pounds of muscle in the offseason, which feels a bit paltry — as color analyst Jay Bilas quipped, Brown looks like he's added eight pounds of muscle in each arm.

The key? His water dumbbell workouts. If you're going to the gym hoping to look like Brown, you may need to find out what your local YMCA's policy is for dumbbells on the high end.

8. You have to make your free throws.

In overtime – in a game the Celtics again lost by three – they went 3 for 6 from the free throw line. The three missed shots included two in a row by Brown, followed by one by Tatum.

9. The Celtics won't go 82-0.

The Celtics were always going to lose at some point, and a road loss to a good Pacers team that was off to a rough start and desperately needed a clean win over a good opponent is as good a starting point as any to enter this column.

“There are two things to focus on,” Mazzulla said. “We need to make sure we perform so we're not half a step behind, but you can see what we're capable of at our best, top to bottom. The boys fought, so that was good.”

The most interesting thing to watch going forward: Can the team as a whole, and Tatum in particular, quickly get out of this shootout and get back on its feet? Tatum's new shooting form looks fantastic, but if it doesn't help him avoid some of the shooting slumps he's experienced in the past, we're mostly talking about the aesthetics.

10. The road ahead

The Celtics continue their road trip with a back-to-back game in Charlotte on Friday and Saturday, followed by a game against the Hawks on Monday.