There’s no doubt that the roles of writer and director are heavily linked, yet many aspects of these two jobs also differ. Directors are responsible for so many elements outside of the script that you could argue that either a) this means they have more tools to bring a story they create to life; or b) that they cannot focus and specialise in the writing process.
Film data hound Stephen Follows sifted through the statistics and discovered three genres that strongly reward writing-directing.