A hit would be a switch for Jennifer Aniston

With the romantic comedy "The Switch" due in theaters Friday, it's time once again to consider the Jennifer Aniston paradox: Why does one of the world's biggest stars make such bad movies?

Aniston has racked up hits, but mostly as a co-star or a supporting player. Her biggest success was the 2003 Jim Carrey comedy "Bruce Almighty," which grossed $242.8 million, according to BoxOfficeMojo.com. Last year, "He's Just Not That Into You" earned $93.9 million. And Aniston's second-biggest hit, 2008's "Marley and Me" ($143 million), starred a Labrador retriever.

At the same time, Aniston has difficulty "carrying" a film. Her 2005 thriller, "Derailed," with Clive Owen, was a flop, as was last year's "Love Happens," with Aaron Eckhart. "Rumor Has It" earned $43 million in 2005.

Another puzzle: The smaller the film, the better Aniston seems to do. Her best reviews have come for roles in independent, character-driven movies like "The Good Girl," a black comedy with John C. Reilly; "Friends With Money," an intelligent comedy that co-starred Frances McDormand and Catherine Keener; and "Management," a quirky comedy-drama with Steve Zahn.

Where does that leave "The Switch," starring Aniston as a single woman planning her pregnancy? It looks partly like the usual Hollywood product. Until the film comes out, the Aniston Paradox continues.