This will be a tough postmortem to perform, if, as it appears more and more likely, exactly how and why the Avalanche fell apart so badly in the second half of this season and missed the playoffs.

I don’t really get it, folks. On Dec. 6, the Avalanche had a 17-7-5 record after a 5-2 win at the BB&T Center in Sunrise, Fla. I was there that night, and I remember the overriding thought I had on the ride back to my Airbnb after writing the story of the game: What seed will the Avs be when the postseason starts?

The Avs were a genuinely exciting team to be around that night. They had a dominant first line, a more improved defense from the playoff squad of a season before, a seemingly strong 1-2 combo in goal and what was an unmistakable air of swagger in the dressing room. Not only that, there was the knowledge that Ottawa’s first-round pick would be theirs in 2019, along with D-men prospects such as Cale Makar and Conor Timmins on the way, plus a bunch of other draft picks.

“This is gonna be fun,” one player confidently told me, in forecasting the near-term future and beyond.

Friday night, the Avalanche dressing room was a morgue. When the final horn sounded on the shocking last-minute collapse and 5-3 loss to the lowly Anaheim Ducks, Avalanche players on the ice all hunched over with their sticks on their knees. That is the time-worn posture of players who know the season just ended.

Technically, it’s not over. But it’s over for the Avs of 2018-19. How did such a young, talented and, most important, confident team from that night in Sunrise see the sun set on its season already? How did this particular Avs team manage to go 13-22-5 after that night? How did we get here?

Barring a miracle, it’ll be a long, painful summer of trying to figure that out.

“If we want to be a playoff team, we’ve got to deserve it, you know? Right now, it doesn’t look like we deserve to be in the playoffs,” said Avs defender Nikita Zadorov, who looked like the frustrated hockey version of Rodin’s The Thinker after the game, staring vacantly into the floor. “It’s hard to win when you don’t play hard for 60 minutes. It’s been hurting us all year. We had a great first period, pretty good third period, but we totally lost the second period. We give up three goals (after getting a 2-0 lead). That’s totally unacceptable I think…We’ve all got to look in the mirror and figure it out.”

The final two minutes and 21 seconds of this game gives something of a big-picture answer of how it all went wrong. A microscosm of the season, since Dec. 6 at least, right in those 141 seconds: A late penalty, an errant stick by Mikko Rantanen, Anaheim on the power play in a 3-3 game. A pretty good PK for the first 1:24, clearing the puck a couple of times, until a defensive breakdown; A pass from the half-boards between the legs of Zadorov, over to the other side of the ice. A late-reacting Avs defense from there. Some scrambling around. A shot on net, stopped by Semyon Varlamov, but a rebound laying in the crease back toward Corey Perry on the other side.

Corey Perry may be old and slowing down, but he doesn’t miss 1-footers with nobody on him. A spirited Avs rally on the ensuing faceoff, a golden chance for J.T. Compher to tie it back up. A point, and maybe another to come, and the Avs are back to within three points of the last playoff spot. But Compher is stopped. Empty-net goal. Game over, Avs players hunched over.

And, probably, season over.

“(Bleep) happens. It’s hockey sometimes. I take responsibility for that,” Rantanen told BSN Denver. “I don’t know. It is what it is I guess.”

Jared Bednar was one pretty frustrated looking man afterward.

“We were checking with our eyes,” Bednar said. “We gotta check with our legs. We were the rested team, but we didn’t win enough races. We didn’t check the puck back enough. We build a lead and it looked like we got comfortable with it, and we stopped working.”

Bednar was plenty critical of his players in the macro sense, but he knows he could be the one blamed for all of this. I don’t think he’s going to be fired over this season, but am I totally confident of that? Uh, this is the NHL. So, no.

I asked him if he’s had to look in the mirror himself over what’s happened and wonder if it’s his message that isn’t working anymore?

“Yeah. We evaluate every day,” Bednar said. “The players, as a staff, what we have to do, what we want to do. We needed a big effort tonight and we got it from some guys and partially from other guys. But that’s a skill; Being consistent is a skill, as a player. We have good players. We have really good players. But being able to do it every night is a skill. We’ve got to work on it. We’ve got to mature to the point where we’re good every night, not just once in a while.”

This game was another microcosm, in the sense that the Avs just didn’t play with any killer instinct, against a team it should have beaten easily. Too many teams came into the Pepsi Center this year and outworked an Avs club that had no excuses for that to be the case. This was a Ducks team that played the night before in Arizona, was playing its third game in four nights and an Avs team that had been off since Monday.

Just like in the season, they got out to a good start in this one, then let up. Then, they played with desperation after losing their cushion. But it was too late.

Why a team that still hasn’t won a playoff round in 11 full years, a team that seemed hungry for more after that unexpected run to the playoffs in 2017-18 but instead fell back into the deadly trap of self-satisfaction?

It’s a mystery, with no good solution, at the moment.