When the awards season began in 2006, no one was really looking at Martin Scorsese’s “The Departed.” But it was poised to become the story of the year.

Most eyes were on big prestige plays like Clint Eastwood’s “Flags of Our Fathers” and Bill Condon’s “Dreamgirls” to potentially take the lead in the Oscar race. Maybe a remake of a 57-year-old Oscar champ from Steven Zaillian (“All the King’s Men”) would register, or Stephen Frears’ ultimate BAFTA favorite “The Queen.” Perhaps the ensemble Emilio Estevez had assembled for his historical drama “Bobby” would catch fire, or Sundance delight “Little Miss Sunshine” would charm its way all the way through.

But Scorsese, while widely perceived as overdue for his first statue, was going back to his roots in the crime/gangster genre that made him, a genre that didn’t necessarily scream Oscar. And the circuit must have appeared exhausting: After two cycles of Miramax projects — 2002’s “Gangs of New York” and 2004’s “The Aviator” — that put him through the awards season grinder, Scorsese was finished chasing Hollywood’s big bauble. He had come to terms with the fact that the Academy doesn’t honor the kinds of films he makes, and his publicist Leslee Dart made it clear at the outset that he wouldn’t be jumping through the usual hoops.

And Warner Bros. wasn’t pushing the issue. The studio that yanked the carpet out from under Scorsese two years prior when “Million Dollar Baby” sneak-attacked the season had yet another Eastwood film on the horizon: “Letters From Iwo Jima,” a companion to “Flags of Our Fathers” that would in due course make its own strong case for the prize.

“The Departed” arrived on Oct. 6 and exceeded both critical and box office expectations. It wasn’t set up for an early fall festival tour. The studio wasn’t overly precious about it. It was treated as a commercial play and the usual bells and whistles of an Oscar campaign were really nowhere to be found. Heavy phase one spending didn’t pick up until December and there was just a single tastemaker event for the film scheduled during the season. It was, in many ways, the non-campaign campaign.

Others might say it’s a scenario that landed in Warners’ lap, and that happens sometimes with commercial movies that aren’t aimed squarely at Oscar glory. Just look at last year, when many at the studio were caught off guard by the awards success of “Mad Max: Fury Road.” But the strategy on “The Departed,” such that it was, was simple: Either you think this guy deserves this honor or you don’t. Another article in the awards press isn’t going to make a difference.

Regardless of whether it was by design or serendipity, “The Departed” charged right on through the season and the obvious narrative took shape: “It’s time for Marty’s Oscar.” Eventually a best director win became a foregone conclusion. The Academy would all too gladly hand him the helmer’s prize for crafting another modern crime classic. (So obvious was this outcome that Scorsese’s filmmaker pals — Francis Ford Coppola, George Lucas and Steven Spielberg — were tapped to present the honor that night.)

Best picture, though, seemed as if it could go to any of the other contenders. The Golden Globes even split their prizes between two top players, “Babel” and “Dreamgirls.” When the latter shockingly failed to land a best picture nomination, however, the tide really started to turn.

Along the way, Jack Nicholson’s seemingly sure-thing supporting actor bid for a scenery-chewing performance fell away. Category confusion likely did Leonardo DiCaprio in: Warner Bros. campaigned him in the supporting field to avoid internal conflict with his leading “Blood Diamond” performance, a strategy that netted him Screen Actors Guild nominations for each. But whereas SAG bows to studio placement, the Hollywood Foreign Press Assn. does not. As such, DiCaprio was Golden Globe-nominated in the lead actor category for both films.

But when it came down to the Academy vote, things shook out unexpectedly. DiCaprio got the lead nod for “Blood Diamond,” but it was Mark Wahlberg’s wisecracking Boston cop that got the supporting bid for “The Departed.”

It’s a shame that DiCaprio, who probably wasn’t complaining, couldn’t also be recognized for his work in Scorsese’s film. It’s arguably his greatest performance to this very day, a wicked display of range and focus that took his career to the next level. Within a decade, however, he’d finally have his Oscar, too.

Going into Oscar night, the best picture category still felt undecided. The Directors Guild of America had unsurprisingly honored Scorsese. The Producers Guild, meanwhile, opted for “Little Miss Sunshine,” which also claimed the SAG ensemble prize. And again, the Globes split between “Babel” and “Dreamgirls.”

My thought was that Eastwood was primed to upset again: Scorsese would get his director prize, but “Letters From Iwo Jima” would stand out as the respectable prestige choice. And it really was a fabulous film, a humanist account of the Battle of Iwo Jima that was artful and refined compared to the high gloss of “Flags of Our Fathers.” It might be Eastwood’s last truly great outing behind the camera.

With such an up-in-the-air year, it felt worth it to make a risky bet, so I bet on “Letters.” The only other person who saw it similarly was Turner Classic Movies personality Robert Osborne, if I recall correctly.

But that was overthinking it. When Nicholson took the stage with Diane Keaton to read the night’s big winner, he looked at the envelope and nonchalantly announced: “And the Oscar goes to — ‘The Departed,’ Graham King, producer.” Keaton screamed with gleeful surprise. Scorsese seemed paralyzed backstage (maybe just wondering if he should join King at the microphone).

It was a different time, a different status quo, but “The Departed” was last film to win best picture without playing the festival game. The Venice-Telluride-Toronto corridor has become an important piece of track laid by recent champions, and yet this rowdy gangster remake from an American icon just didn’t need it. It didn’t need to “position itself.” It didn’t need to do anything other than play.

And that, to me, is the lesson of “The Departed.” Sometimes all you need to win best picture is a damn good movie that plays.