Game 7 analysis: The Celtics' worst habits surfaced at worst time

For the past week, the Celtics have talked about how this was their chance to make history, their chance to do something no team has ever done.

And when they roared out of a 3-0 deficit in the Eastern Conference finals against the Heat and returned home for a Game 7 on Monday night, it was hard to envision a scenario in which things would crumble after coming so far.

But this team’s erratic, inconsistent play plagued it all season, and it resurfaced at the worst possible time. The Heat pummeled the Celtics, 103-84, at TD Garden, ending their quest to become the first team in 151 tries to climb out of a 3-0 playoff series hole. And, more importantly, it dashed the championship dreams once again.

The Heat advance to the NBA Finals, where they will face the Denver Nuggets.

Celtics star Jayson Tatum twisted his ankle on the first possession of the game and was never the same again, held to 14 points on 5 of 13 shooting. Jaylen Brown made 8 of 23 shots for 19 points, and coughed up eight turnovers. The Celtics started the game by missing 12 3-pointers in a row.

Jimmy Butler led Miami with 28 points and Caleb Martin added 26.

Observations from the game:

⋅ Tatum was fouled by Gabe Vincent on Boston’s first possession of the game and appeared to twist his left ankle when he landed. He remained down as the fans chanted his last name before he was eventually helped up. Tatum stayed in the game, but he didn’t have his usual burst over the rest of the game, either. He went to halftime with just 7 points and wasn’t able to create separation in the second half, either.

⋅ Tatum checked out with about four minutes left in the first quarter and was slated to receive a very brief rest. He went to the scorer’s table with 2:30 left, but there wasn’t another dead-ball in the quarter and Boston was outscored by 5 points over the rest of the frame.

⋅ Brown got Boston’s offense started with a couple of early buckets, but things unraveled quickly for him after that, as he returned to his bad habit of dribbling into traffic with his head down and no real idea of where he wants to go. Brown had three of the Celtics’ seven first-half turnovers and in the second half just appeared lost, firing up careless jumpers that had no chance and committing five more turnovers. One of his worst nights as a Celtic.

⋅ Malcolm Brogdon returned after missing Game 6 because of a lingering right forearm issue. He struggled mightily in Games 3-5, held to a total of 2 points, and in the first half it appeared he still wasn’t quite right. He airballed his first 3-pointer by about two feet, smoked an open layup, and threw an errant pass to Tatum that led to a turnover. Boston was outscored by 15 points during his seven-minute stint.

⋅ When the Celtics won Game 6 after making just 7 of 35 3-pointers, a season-low 20 percent, it did not bode well for the Heat. The Celtics would surely not shoot that poorly again, and even if they did, they showed they could overcome it. Then they somehow started Game 7 by going 0 for 12 from beyond the arc. There were plenty of open looks by good shooters, but Tatum attempted just one of the threes.

⋅ Opponents have complained about Bam Adebayo’s screens throughout these playoffs, and he was whistled for one with 2:41 left in the second quarter, a pretty substantial call because it was his third foul. For the first time in the series, Heat coach Erik Spoelstra did not go to backup center Cody Zeller, whose minutes have been a disaster. Instead, he went small with Haywood Highsmith. The Celtics sliced just 2 points off of Miami’s lead during this stretch, though, and foul trouble was not an issue for Adebayo in the second half.

⋅ Celtics coach Joe Mazzulla, meanwhile, went to a double-big lineup for parts of the first half, with Robert Williams and Al Horford sharing the court. The Heat took advantage by sending wings slicing to the hoop. But it was a strong first half for Williams overall, with 6 points, 3 rebounds, and a block.

⋅ Despite the Celtics’ slow first half, they trailed by just 11 points at the break. A very manageable deficit. But the start of the third quarter was not great, with Butler quickly extending the Miami lead with a 3-pointer and a runner. Those 5-point swings one way or another are just huge at the start of a quarter.

⋅ With Tatum and Brown struggling, Derrick White gave Boston a chance in the third quarter, riding the high from his Game 6 buzzer-beater. In just over one minute he hit a pair of free throws and a 3-pointer and converted a 3-point play, pulling the Celtics within 59-51. When he went to the foul line later in the quarter he was serenaded with “MVP” chants. Usually those are kind of a joke for players like him, but not in this case.

⋅ The Celtics are going to have nightmares about Martin all summer. He crushed them throughout the series, but saved his best for Game 7. It seemed he simply did not miss a single open shot, and he made the ones that were tougher, too. His biggest stretch started at the end of the third quarter, after White gave Boston life. He closed the quarter with a 3-pointer and a baseline jumper, then started the fourth with another three after Tatum smoked a layup.

⋅ The Heat are just so good at the small details. The Celtics thrive in two-for-one situations in which they take the first shot with about 31 seconds left at the end of a quarter. But Miami slowed down its own two-for-ones at the end of the second and third quarters to stop Boston from doing it. The Heat also applied constant ball pressure in the backcourt, both to stop Boston’s pace and force them to start their offense later in the possession.

Instant analysis: The Celtics’ worst habits showed up at the worst possible time, and their season is over

Read more about the end of the Celtics’ season