There is a stellar acting career and tons of Ben Affleck movies that the actor can be proud of, starting with his breakout movie, Good Will Hunting, with buddy Matt Damon. But for his latest role, director David Fincher zeroed in on one of Ben's traits: his smile. You'd think that it would take a lot more to convince the Fight Club director to cast someone in the crucial role of Nick Dunne, a man who is accused of murdering his wife.

But the Gone Girl role had to go to someone whose smile is a pivotal point in the thriller based on Gillian Flynn's bestselling novel of the same title. In the latest Ben Affleck movie, the director was able to cast him via a bit of stalking on Google. Fincher recently did an interview with Playboy magazine to promote his latest movie Gone Girl. In the said interview, Fincher revealed how he decided to choose Affleck as the lead character in the movie.

"You cast movies based on critical scenes," the director says says. "In Gone Girl there's a smile the guy has to give when the local press asks him to stand next to a poster of his missing wife. I flipped through Google Images and found about 50 shots of Affleck giving that kind of smile in public situations. You look at them and know he's trying to make people comfortable in the moment, but by doing that he's making himself vulnerable to people having other perceptions about him."

Fincher further explains how they asked the actor to do this particular scene. "What we asked him to do was 'Open vise, insert testicles and turn' for the entire length of the movie." It's one of the most chilling scenes in the book, as readers of the novel already know. And it was just key that a good actor be able to pull off the infamous Nick Dunne smile.

Fans of the book are also a bit way of this new Ben Affleck movie of their favorite novel, as news leaked a couple of months back that the ending has been completely altered.