An actor has a great opportunity to mold a character into the way they see it in their mind. A great power, with a great responsibility. That can potentially make or break a movie or show. A good director knows that, and often casts actors in roles they didn’t envision themselves in.
Buzzfeed recently released a list of actors who auditioned for a role they didn’t get. But, they got another role in the same show. And from the shows on the list, it shows those directors knew what they were doing.