But if you look more closely at Affleck's work, it makes more sense. Not because he's been at his best in blockbuster parts, but because, in everything from the indie comedy Dogma to the domestic thriller Changing Lanes, he is exceptionally good at the one thing that defines Batman: rage.
"I think it's a necessity, historically, in the tradition of these films," he says reflecting on the character's combustible temperament. "For me, anger is so deeply buried and contained that when it does kind of come out, it comes out in stronger bursts. I tend to be respectful, polite, get along, put up with, put up with, put up with ... then, when it finally emerges, it's not something I have a ton of control over. I'm not gonna go into a Wolverine berserker rage, but I do have a, I do..." He trails off, thinking - perhaps a little surprised - before murmuring: "That is an interesting thing that you point out. That's my personality."
He quickly clarifies, in case this seems like a boast: "By the way, that's a character flaw, I think. I should sit down and say, 'Listen, I just want to let you know what happened there wasn't OK, instead of going, let it go, let it go, let it go ... "Ah, that's not a big deal', until finally you just pop!"
Audiences will see this in Gone Girl: the anger in the everyman. It's a remarkable, vanity-free performance. And it bodes well for his interpretation of the Dark Knight. As the poet John Dryden once had it: "Beware the fury of a patient man." Or Batman.