The Miami Heat’s MVP may be its coach, Erik Spoelstra

But if the Celtics somehow fumble away the advantage of playing this win-or-else game on their home court, then Joe Mazzulla will be considered the overmatched rookie coach who couldn’t steady the ship. Mazzulla, after abruptly taking over for Ime Udoka just before the start of the preseason, will have inherited two all-NBA players and a rock solid core from last year’s Finals team only to drag it down to the second round.

All the while, however, Erik Spoelstra will be somewhere in Miami, unscathed by criticism while on his way to yet another conference finals.

With the Miami Heat becoming just the second eight-seed to make it this far, there are plenty of MVPs to thank. First, Giannis Antetokounmpo’s back injury that limited him and the top-seeded Milwaukee Bucks during the Heat’s first-round upset. Then, the New York Knicks for playing wholly incompetent offensive basketball. Also, of course, Miami’s Jimmy Butler, for raising his game in the playoffs (even though he’s not a fan of his “Playoff Jimmy” moniker.)

Mostly, the Heat’s most valuable person this postseason — and really, since the end of the Big Three run — has been the 52-year-old at the head of the bench. This will be Miami’s seventh conference finals appearance under Spoelstra, and the third in the past four years. He has come a long way from the film room.

Those photos of a baby-faced Spoelstra surrounded by VHS tapes seem to emerge whenever he gets this far. As though we need visual reminders that Spoelstra does not have NBA playing experience that helps inform his knowledge as a coach — like Rivers, Rick Carlisle and Steve Kerr. Or that he shouldn’t naturally deserve respect the way a gruff, white-bearded veteran might — like San Antonio’s Gregg Popovich, the standard in NBA coaching with 1,364 wins. Or even the man who hired him 15 years ago.

“This closeout game was a nod to our president [Pat Riley],” Spoelstra said after Miami’s 96-92 win over the Knicks on Friday night. “That was fully in his image and personality.”

Though Spoelstra may dutifully tip his cap to Riley, his mentor, he doesn’t get enough credit for impacting the development of the current roster, as well as continuing the team’s hard-to-define culture.

During Game 6, an experience that set basketball back 30 years, Miami forced the Knicks into a plan as predictable as the “Pass It to Will” offense run by Bel-Air Academy. If point guard Jalen Brunson wasn’t scoring, then New York could find no spark, no variety, no life from anyone else. Brunson accounted for the Knicks’ only two made shots through more than 8½ minutes of play of the final quarter.

New York ended the game with just two more field goals, and though the Heat also lacked inspired shot making, it persisted through its identity. A team president such as Riley, who built this gritty team, theoretically has only so much say in crafting results from the roster. It has been Spoelstra who has worked his magic over this group.

It’s a Heat team that lost, at home, in a play-in game to the Atlanta Hawks, then needed a big run late to beat the Chicago Bulls in another just to earn the right to face the best team in the East during the regular season, the Bucks. That series barely broke in before Miami started losing its depth, first with former sixth man of the year Tyler Herro fracturing his hand, then Victor Oladipo tearing the patellar tendon in his left knee. Through all of this, the Heat survived, thanks in part to a few mega games from Butler but also the steadiness from its coach.

“You hope adversity brings a group together rather than take away their spirit,” Spoelstra told reporters Friday. “I had that feeling for the last three months of the regular season, but then it was cemented in my mind after we lost the Atlanta game. Soon as I walked into the film session the next day, I knew how badly our team wanted to keep this thing going. That’s a spirit thing you always hope you cultivate in your team. It doesn’t always happen, and that’s why you’re just grateful for this opportunity to represent the Eastern Conference in the Eastern Conference finals.”

In a league that treats coaches as disposable as game-used tape, Spoelstra, the film-room kid, has remained. While Spoelstra’s lowly beginnings help fluff up his story arc from the video room to the Heat’s sideline, the fairy-tale rise should no longer define him.

Miami has the best coach remaining in the playoffs. And this advantage cannot be emphasized enough as game-to-game adjustments, late timeout usage and overall trust among the players will become paramount.

The 76ers have Rivers, but his one championship ring can no longer gloss over a streaky playoff record that includes not leading a team past the second round since 2012, when he was with the Celtics. Though Mazzulla didn’t mess up much while Boston ascended to the second seed in the conference, its regular season success masked many of his flaws — namely, his late-game decisions — that have been exposed in the playoffs.

In Miami, however, there’s no pending angst from the fan base. Spoelstra may still look younger than his age and experience suggest, but over the past decade he has proved his worth as a trustworthy leader on the sidelines.