Every year, Hollywood delivers a handful of movies that are "based on a true story," and every year, a number of them become front-runners for Oscars. Unfortunately for Hollywood, that leads to yet another annual tradition: Experts and real-life counterparts weighing in and picking nits.

It doesn't seem to hurt anyone's Oscar chances. Last year, Zero Dark Thirty, Argo, and Lincoln picked up an admirable number of nominations and prizes among them, despite misgivings about their accuracy.

So how realistic are some of this year's "based on a true story" Oscar contenders? Let's fact-check this year's lineup:

1. The Butler
Lee Daniels directed this portrayal of Eugene Allen, an African-American butler who worked at the White House over the course of eight presidential administrations, and consequently was a fly-on-the-wall witness to landmark civil rights battles and other major events in U.S. history. The movie takes a few liberties from the start: For one thing, the name of the protagonist was changed to Cecil Gaines. For another, many of the characters are composites of real people. "I felt by combining all of these different stories, I would be able to create a more universal experience for the audience of what it meant to be a member of the White House staff during these extremely tumultuous times," said screenwriter Danny Strong.

One big invention was the depiction of Gaines' son as a Black Panther, which becomes a primary source of dramatic conflict in the movie. "Though tension between father and son over civil rights issues fuels most of the drama in the film, Charles Allen was not the radical political activist that Gaines' son is in the movie," writes Eliana Dockterman at TIME. "Charles Allen worked as an investigator for the State Department and never ran for public office."

2. Saving Mr. Banks
The making of Mary Poppins was famously rocky. Creator P.L. Travers wrote the first book in 1934, but it took another 30 years for Walt Disney to finally release the now-beloved movie version. Saving Mr. Banks follows the story behind the story, tracking the ups and down of the Travers-Disney relationship as portrayed by Emma Thompson and Tom Hanks.

But though there is much truth to the tale, the film is also "corporate myth-making on a large scale," as Drew McWeeny writes for HitFix, since it mostly glosses over the real-life personality of Disney. "The difficult part of Walt Disney Studios telling this story is that they have a vested interest in making sure that Walt Disney, the icon, emerges from this as the hero of the story," he writes.

Alex von Tunzelmann expands on this at The Guardian: "The film goes soft on Uncle Walt, who by many accounts may have been less sweet-natured than he is portrayed here."

Also: Disney was a notorious chain smoker, which was entirely left out of the movie, complying with modern Hollywood's unwritten rule that only bad guys can smoke.

3. 12 Years A Slave
Based on the story of Solomon Northup — a free man who was kidnapped and sold into slavery for 12 years — the accuracy of 12 Years A Slave has been questioned mostly because that of its source material has also been questioned. Northup's account of his time enslaved in Louisiana has been the subject of much scholarly study over the years, because at the time of the book's writing there existed "pressures that created a certain uniformity of content in the popular slave narratives," as The New York Times explains, "with recurring themes that involved insistence on sometimes questioned personal identity, harrowing descriptions of oppression, and open advocacy for the abolitionist cause."

But, as Forrest Wickman writes for Slate, "salient facts were authenticated by the historian Sue Eakin and Joseph Logsdon for their landmark 1968 edition of the book." As for the movie itself, Wickman writes that while "much of the story is condensed, and a few small scenes are invented, nearly all of the most unbelievable details come straight from the book, and many lines are taken verbatim."

One particular scene that was purely fiction: A female slave named Patsey, the favorite of slave owner Edwin Epps ("favorite" being something of a euphemism, as Patsey would as often evoke Epps' affection as his violent, jealous rage), asks Solomon to kill her. "Her request afterward that Northup kill her, to put her out of her misery, is the movie's own invention, but it's a logical one: Patsey is described as falling into a deep depression and, it's implied, dreaming of the relief death would offer her," writes Wickman.

4. Mandela: Long Walk To Freedom
Much of the publicity surrounding Idris Elba's turn as Nelson Mandela comes from the timing of the film's release, which in a sad coincidence occurred just before the actual Mandela passed away. The movie, very closely based on Mandela's autobiography, tells a broad and fairly complete story of the South African freedom fighter's political work and long imprisonment.

If anything, some critics argue that it's a little too broad, covering so much ground that it glosses over some key details. "In trying to fit in so much, the film suffers in some respects — for example the characterization of the 'comrades' imprisoned with Mandela, and therefore the relationships between the men," writes Sally Williams at The Telegraph. "Nor is there a thorough accounting of how Mandela came to found the African National Congress's guerrilla force — known simply as MK — and become its commander-in-chief. Nor of how the trade-union movement mobilized mass campaigns of resistance and economic boycott that, along with international pressure, contributed to Mandela's release."

And as Andrew O'Hehir argues at Salon, the film leaves out some difficult truths about Mandela: "Unsurprisingly, Chadwick's film skips lightly over the whole period when Mandela was closely allied with Marxist and/or anti-colonial revolutionaries all over the world, from sub-Saharan Africa to Palestine to Latin America to Northern Ireland."

5. Philomena
Dame Judi Dench and Steve Coogan star as unlikely road trip buddies in this story of Philomena Lee, an Irish woman who goes looking for her long-lost son. Lee was sent to a convent as a pregnant teenager in 1952 and forced to sign away the rights to her child, who was then adopted by a couple in the U.S. Coogan plays a former reporter for the BBC, Martin Sixsmith, who follows Philomena to the U.S. as she searches for her son, and then writes a book about it.

The film has taken some criticism for its portrayal of Catholics (not to mention Republicans), as the convent nuns become the de facto villains in the story. As Alex von Tunzelmann writes for The Guardian, "The Catholic Church doesn't come out of this story well however you slice it, but in the book its cruelty seems to be largely in the past. 'The nuns were lovely,' writes the real Sixsmith, after visiting Roscrea with Philomena. He describes the mother superior as 'a friendly, educated woman… who had devoted her life to the care of disadvantaged and disabled people.' This doesn't come across at all in the film."

The nuns themselves have come forward and decried certain aspects of the film. "We do feel however that the film, even though it is not a documentary, does not tell the whole truth and in many ways is very misleading," Sister Julie Rose of the Sacred Hearts of Jesus and Mary told Sarah MacDonald of the Irish Independent. And Kyle Smith of the New York Post somewhat less diplomatically described it as a "diabolical-Catholics film, straight up."

The real Lee addressed the criticism in a letter: "The story it tells has resonated with people not because it's some mockery of ideas or institutions that they're in disagreement with. This is not a rally cry against the church or politics. In fact, despite some of the troubles that befell me as a young girl, I have always maintained a very strong hold on my faith."

6. Captain Phillips
Tom Hanks makes it into another movie of questionable veracity in Captain Phillips, playing Richard Phillips, captain of the Maersk Alabama, a cargo ship that was taken hostage by Somali pirates in April 2009. Though many of the film's details have been taken straight from Phillips' account of the harrowing incident, some of the crew members have disputed his version of the attack, albeit anonymously. "Phillips wasn't the big leader like he is in the movie," one anonymous crew member told the New York Post, adding, "No one wants to sail with him."

Writes Forrest Wickman for Slate: "Many of Phillips' crew members, some of whom are in the midst of a lawsuit they filed against the ship's owners, claim his account misrepresents the story. According to them, Phillips behaved irresponsibly: They say he ignored warnings about pirates in the area and sailed too close to the Somali coast. One of Phillips' crew, a man who goes by the name ATM, has also claimed that he alerted Phillips to the pirates only to have Phillips dismiss him... Phillips denies this."

Paul Greengrass, the film's director, responded to the anonymous crew members in a Reddit Ask Me Anything. "When we started the film, it was a top priority for me to look into this issue in every detail," he said, adding that he and his partner "researched the background of the Maersk Alabama highjacking [sic] in exhausting detail over many months. We spoke to every member of the Alabama crew bar one, all of the U.S. military responders that played a leading role in these events, and thoroughly researched backgrounds of the four pirates and the issue of Somali piracy generally. And I'm 100 percent satisfied that the picture we present of these events in the film, including the role playing by Captain Phillips, is authentic. I stand by the picture I give in the film, absolutely."