It’s pretty well known that Ben Affleck is a devoted Boston Red Sox fan. Those who saw the actor in Gone Girl over the weekend may have been amused by his character wearing a St. Louis Cardinals t-shirt (the story takes place in a fictional Missouri town) or concealing his identity with a New York Mets cap.
As it turns out, some discussion between Affleck and director David Fincher went into that particular cap choice. Fincher wanted Affleck to wear a New York Yankees cap, believing that worked best for the story. (At that point in the movie, Affleck is visiting New York incognito.) But the diehard Red Sox fan wanted no part of that fashion choice.
Affleck went so far as to call it a “legitimate fight” when talking to the New York Times‘ Cara Buckley.
“I said, ‘David, I love you, I would do anything for you,’” Mr. Affleck recalled. “‘But I will not wear a Yankees hat. I just can’t. I can’t wear it because it’s going to become a thing, David. I will never hear the end of it. I can’t do it.’ And I couldn’t put it on my head.”
As you can see in this screen cap from the trailer, Affleck and Fincher eventually reached a compromise: A Mets cap.