I was watching an interview with Martin Scorcese concerning Raging Bull, which is one of my favorite films, and he was talking about how he'd worked with a lot of guys who weren't quote-unquote "actors," like Joe Pesce and Frank Vincent. Scorcese was very smart in the way that he cast, because you don't know where you're going to find the right person who can carry a role and summon that emotion you're looking for.