Let’s face it, the Celtics are not as good as they think they are

The 2020 playoffs go down as a wasted opportunity. The 2020 Celtics had more talent than the Heat, but the Heat worked harder and won every contested game. The Celtics had leads of 14 and 17 points in Games 1 and 2 and lost ‘em both. Boston led Game 6 by 6 points in the fourth quarter, then folded like a cardbox box in a hurricane. The Heat became the first No. 5 seed to advance to the Finals in this century.

Please let’s not frame this as a learning experience for a young team.

No. This was a wasted opportunity. The Celtics had the talent to win this series. They underachieved. Wildly.

“Obviously we feel like we underachieved,’’ acknowledged Jaylen Brown.

Good start there.

Admittedly, we are spoiled here in Boston. No local team has won a championship since the Patriots won Super Bowl 53 some 17 months ago. The local sports high renaissance is stalled. Things haven’t been quite right since Brad Marchand skated off the ice early at the end of the first period of the seventh game of the 2019 Stanley Cup Final.

Game 6 of the 2020 Eastern Conference finals was a field day for the Heat and an epic collapse by the Celtics. Boston led, 96-90, two minutes into the fourth quarter, then got pantsed by Bam Adebayo (32 points, 14 rebounds), Jimmy Butler, Andre Iguodala, Tyler Herro and Duncan Robinson. Miami outscored Boston, 35-17, in the final nine minutes. Adebayo — a John Calipari discovery at Kentucky who was drafted the same year as Tatum — laid waste to Boston’s non-centers down the stretch.

“They made the plays and we didn’t,” said Celtics point guard Kemba Walker.

It was not a good ending for Brad Stevens and his young warriors, Jayson Tatum (24 points), Brown (26) and Marcus Smart (20). Veteran Gordon Hayward, perhaps still hindered by an ankle sprain, was particularly disappointing and crushed the Celtics every time he was on the floor. As in other losses, the soft Celtics resorted to hero ball when things got tough. In a COVID-19 season that lasted more than a year and put the Celtics in the Orlando bubble for 11 weeks, Boston lost seven of its last 11 games.

Class act that he is, Stevens was predictably forgiving. He said he appreciated everything about his team.

“I appreciated the way they played basketball all year, the way they competed, the way they blocked out stuff that doesn’t matter,” said the coach. “. . . I appreciated the way they played and found joy and stayed together.”

Game 6 was like the other three games the Celtics lost in this series.

The Celtics played with lack of urgency from the jump. They cruised. They lollygagged. They played like they knew they were better and waited for the good times to kick in. Tatum missed his first seven shots, which made him 0 for 13 in the first quarters of Games 4, 5 and 6.

The good news was Tatum did everything else and eventually got hot. He wound up with a Magic Johnson stat line in the first two quarters: 12 points, 8 assists, 6 rebounds, 2 steals. Boston trailed by 2 at intermission.

Paul Pierce crushed his Celtic progeny on ESPN at the halftime, exhorting them to play some defense in the second half. Pierce’s ESPN teammate, Rachel Nichols, reported that Tatum was getting playoff advice from former teammates and eternal Boston pariah, Kyrie Irving. Swell. That explains a lot. Why not call Sidney Wicks, Curtis Rowe and Adrian Gonzalez while you’re at it? A Brown 3-pointer gave the Celtics a 63-62 lead at the start of the third.

Iguodala, who played in five consecutive NBA Finals with the Warriors, ripped a bunch of treys in the third and Miami led, 82-74, when Stevens called time with 4:19 left in the third. Iguodala at that juncture was 5 for 5, including four from international waters. He has played 160 playoff games, second only to LeBron among active players.

A fast-break dunk by Brown after a steal gave Boston a 96-90 lead with nine minutes left. Then came the collapse.

The Celtics have a lot of good young players. But this season goes down as a disappointment. The Celtics had a golden opportunity to play the Lakers in the NBA Finals, but lost to a No. five seed that played harder and wanted it more.

In the midnight hour, the Globe’s Gary Washburn asked Tatum if the Celtics need to get tougher.

“No, we don’t need to get tougher,” responded Tatum.

Unfortunate.

These Celtics need to face the fact that they are not as good as they think they are.

Dan Shaughnessy is a Globe columnist. He can be reached at daniel.shaughnessy@globe.com. Follow him on Twitter @dan_shaughnessy.