Overtime dominance, Kyrie’s dancing, Tatum’s reflection, and other Celtics thoughts

Jayson Tatum had 23 points in Tuesday night’s win.Matthew J. Lee/Globe staff

After 76ers guard JJ Redick’s potentially game-winning 18-footer swirled around the rim and out on the final play of regulation on Tuesday, the Celtics had to feel quite confident about what would transpire next.

Boston has been the NBA’s most dominant overtime team this season, and this matchup would provide that latest example, as the Celtics allowed just 1 point over the final 3 minutes, 32 seconds and closed the game on a 13-1 run en route to their 121-114 win.

“In overtime, the attention to detail in that starting five is high,” forward Marcus Morris said. “We’re just making plays and getting the ball into guys’ hands to make plays. We understand each other’s games, so the spacing is always correct and guys are making the right plays, and it always leads to winning.”

So far this season, it is impossible to argue Morris’s final point. The Celtics are now 4-0 in overtime games, with wins over the Sixers, Raptors, Wizards and Suns. In fact, a whopping 20 percent of Boston’s wins have come in overtime.

The Celtics’ statistics in extra sessions are startling. They are outscoring opponents by an average of 63.4 points per 100 possessions over 20 overtime minutes, by far the league’s best net rating in these situations. They have made 21 of 35 shots, 7 of 10 3-pointers and 13 of 14 free throws. Also, the Celtics have committed just two overtime turnovers, neither of which resulted in a point for the opposition.

The overtime surges, unsurprisingly, have been keyed by point guard Kyrie Irving. He had the two defining moments of Tuesday’s win, when he poured in a pair of 3-pointers to quickly turn a 2-point deficit into a 4-point lead that would not be relinquished. And that has mostly been the norm for Irving in these situations this season.

Irving has played all 20 overtime minutes for the Celtics — save for the final 12 seconds Tuesday to receive a deserved ovation. He has made 10 of 16 overtime shots, 4 of 5 3-pointers, 4 of 4 free throws and scored 28 points. Furthermore, Irving has dished out seven assists and committed just one turnover, with the Celtics holding a 62-36 edge on the scoreboard overall.

Coach Brad Stevens would probably rather see his team close these games without being tied at the end of regulation. But it has to give the Celtics some comfort to know that when overtime arrives, they will be ready.

“For whatever reason, at the end of the game a sense of urgency goes up for our group,” Al Horford said, “and we’re more focused on the little things and the things we need to do.”

Here are some other thoughts, observations and stats about the Celtics:

■  Irving attempted 33 shots on Tuesday, tied for the second most in his eight-year career, including the playoffs. Irving has consistently said how he has been willing to dial back his playing time and shot attempts for the good of the team. But there are also times when it is just best to let Kyrie be Kyrie.

■  In the Celtics locker room after the game, it was clear that they understood these are not the same 76ers that they flicked away in last season’s conference semifinals, or even on opening night this season, before Philadelphia had acquired Jimmy Butler. Or, as Morris put it: “No disrespect to [former Sixer Dario] Saric and those guys. I just think last year they couldn’t defend us at all. They didn’t have the versatile guys that could defend us.”

■  It’s always fascinating to see NBA shooters get a bit rattled when they’re simply too open. Morris has been a lethal 3-point marksman this season, and on Tuesday he had one opportunity where he caught the ball beyond the 3-point arc and no Philadelphia players even feigned interest in defending him. Morris squared up, waited, then took a dribble, and waited some more, and then missed. Similarly, Irving said he was surprised to see how much the 76ers were sagging off him after screens. It was uncomfortable.

“For me, mentally, it was kind of messing me up being that wide open coming off of certain pin-downs and pick-and-rolls,” he said. “I’m usually getting blitzed or guys are up to touch coming off. I just wasn’t dialed in enough.”

This is not to say, of course, that it is ever a wise move to leave Irving open.

“I made them when it counted,” he said.

■  I’ve watched the replay a few times, and am still amazed that Irving was able to get off — and make — his game-tying shot that ultimately sent the game to overtime. With Butler hounding him, Irving danced and darted and put the ball between his legs and behind his back, and he ended up near the foul line. At that point, it appeared that he lost his balance and his footing, with his left leg appearing to slip out from under him as he stepped backward. But then he gathered himself and took two more dribbles and hit the fadeaway. For most players, that would look like a recovery from a misstep. But with Irving, it’s always fair to wonder if that was all part of his move.

■  The Celtics’ early-season starting lineup of Irving, Gordon Hayward, Jaylen Brown, Jayson Tatum and Horford and the more recent group in which Morris and Marcus Smart have replaced Hayward and Brown are the team’s two most-used five-man groupings this season, with more than twice as many minutes as the next closest group. In 139 total minutes, the Irving/Hayward/Brown/Tatum/Horford unit has a minus-1.7 net rating, and in 108 minutes, Irving/Smart/Morris/Tatum/Horford have a plus-19.2.

■  This play was forgotten because the Celtics stormed back from a 5-point overtime deficit to take the win, but Smart’s shove of Ben Simmons that resulted in a technical foul could have been quite costly. The Celtics need Smart’s fire, but they also need him to know when to smother it.

■  Although Tatum had 23 points on Tuesday, he was 7 for 18 from the field and just 1 for 7 on 3-pointers. This was an interesting moment of self-reflection by Tatum after the game.

“I didn’t shoot it as well as I would have liked to,” he said. “For me, I think my next step as a player — I admire all the top players in the league and how they affect the game if they are not scoring. They just try to help their team win. That’s what I am trying to be, just trying to affect the game any way possible, rebounding, getting a block or trying to get a stop even when your shot isn’t falling.”

■  When Hayward torched the Timberwolves with 30 points, 9 rebounds and 8 assists on Dec. 1, there was a sense that maybe the former All-Star was on the verge of recapturing the form he displayed prior to suffering his gruesome ankle injury of last season. But the past month has shown that it remains a work in progress for Hayward. Since that win over Minnesota, Hayward is averaging 9 points, 3.8 rebounds and 3 assists while shooting just 34.3 percent from the field.