Tom Cruise seems like the perfect choice of actor to star in an fast-paced action flick about an ex military police man, right?

Not so, according to author Lee Child, who wrote the novel One Shot (2005), for which the upcoming Jack Reacher film will be be based on. According to the Washington Post, Child recently talked at length about the difficult casting choices for the film. The biggest trouble with casting the title character was not finding someone who could act the part, but rather, someone who could look the part. The book-version Jack Reacher is 6 feet 5 inches tall and weighs 230 pounds. Hollywood isn’t exactly known for its diversity and finding an actor that tall and imposing had been a real struggle. While Child himself wasn’t part of the casting team, he did have some input and all of the choices on the table – from Liam Neeson, Daniel Craig and Denzel Washington to Will Smith or Gerard Butler – seemed like bad choices to him at the time. To Child, the physical presence of the character was a really important aspect of his personality and that would simply be lost with a 5’9’’ actor being cast as Jack Reacher.

Enter Tom Cruise. The actor’s 5’7’’ height has become something of a good-natured anecdote around Hollywood, with him usually playing impressive, domineering characters, regardless of his comparatively small size. So how did Cruise end up with the part, despite the vast physical disparity? Child explains that the casting team simply had a change of heart, deciding that they could go for every other aspect of Reacher’s personality – intelligence, intimidating presence – and put aside the height issue. Whether this decision has paid off will become clear soon enough.

Jack Reacher’s premiere has unfortunately been postponed in light of the recent Connecticut shooting, but the film is set to hit US theaters on the 21st.