In 2009, the Academy of Motion Picture Arts & Sciences expanded Oscar’s best pic contenders from five to 10. Then-president Sid Ganis hoped this would open the category to animation, foreign-language films and documentaries.

Animation and international have scored a few best-picture noms, but docus remain the final frontier. Maybe 2019 is the year when they make it. There are certainly films this year worth consideration. Exhibit A: “Tell Me Who I Am,” directed by Ed Perkins and produced by Simon Chinn.

The story centers on identical twins, Alex and Marcus Lewis. After an accident, 18-year-old Alex went into a coma. When he awoke, he had no memory and recognized no one, except his brother. So Marcus began filling him in, in essence creating a lifetime of memories. It’s a gripping, emotional story, enhanced by expert filmmaking and its virtues stand as a good example of the unique beauty of documentaries.

Back on Feb. 10, 1942, Variety reported AMPAS was inaugurating awards for doc features and shorts, “stressing the growing importance of this class of production.” The importance has grown. In the early days, many docus were in the broccoli-is-good-for-you category: Worthwhile, but a little boring, such as “Journey Into Medicine” and “I Was a Communist for the FBI.”

Docus blossomed in the 1960s and ’70s, with such titles as “In the Year of the Pig,” “Woodstock” and “Harlan County U.S.A.” Now, thanks to savvy storytelling and affordable equipment, voters are faced with a flood of great docus.

Conventional wisdom says the Academy’s doc branch (with 320 members last year) frowns at any movie that’s too successful or deals with the entertainment industry. That’s possible, but then how to explain the nominations for 2002’s “Bowling for Columbine” ($58 million at the box office) and 2005’s “March of the Penguins” ($127 million)? As for showbiz, there have been such recent Oscar winners as “Searching for Sugar Man” (2012), “20 Feet From Stardom” (2013) and “Amy” (2015).

For best pic this year, aside from “Tell Me,” consider “One Child Nation,” a personal look at a community’s reaction to China’s one-child-only policy, and also “63 Up,” from the extraordinary Michael Apted. It’s the latest in his docu series that started with “7 Up.” and in December it will mark an auspicious theatrical debut for the newish BritBox.

Ava DuVernay’s “13th” (2016) and Peter Jackson’s “They Shall Not Grow Old” (2018) are not just excellent documentaries; they’re two of the decade’s best films, period.And a reminder: Documentaries are also eligible in other categories, such as editing, sound, music score, cinematography, etc.

In that regard, 2015 is notable, with two of the five nominated songs coming from docs, “Racing Extinction” and “The Hunting Ground.” Last year, Diane Warren was nominated for “I’ll Fight” from “RBG.”

Next stop for docus: a best picture nomination.