For math and science exams, we were often required to “show our work” — not merely to prove we weren’t cheating, but to demonstrate we understood the underlying principles involved.

I’ve been thinking about this in relation to screenwriting. When it comes to making a film, the screenwriter’s craft is probably the most direct and transparent. What did you do? You wrote the script, the 120-or-so pages of Courier around which everything else revolves. Your work is front-and-center.

Cinematographers, production designers and editors can’t point to a product which is “theirs.” In the finished film, the light is lovely; the world is stunning; the pacing is tight. All wonderful accomplishments, but inextricably bound to the work of others. That wonderful light would go unnoticed if it didn’t highlight the sets, and the sets would be meaningless if the editor favored close-ups. And the contribution of directors, who marshall all these forces in addition to actors’ performances, is probably the most difficult to judge.

As a concise, pre-existing document, the screenplay is probably the only thing that can be judged independently of the finished film. Put another way, the screenwriter shows his work.

But the irony is, after the film is made, no one asks to see his work.

Indeed, we award “best screenplay” based on a viewing of the finished film. If the movie was good, we figure the screenplay was probably pretty good. We guess. Even though we don’t need to guess, because the screenplays for “award contender” movies are commonly available. But frankly, it would be a lot of work to read all those screenplays, so we don’t make that a requirement, even for the WGA Awards. The more honest award would be titled, “Best Film based on a Screenplay which was Probably Good, and Presumably Didn’t Get Messed Up by the Director or Others.”

Worse, we also presume that a bad movie came from a bad screenplay. At some point, I’ll fund a comprehensive study of film reviews from the past 10 years, tracking exactly how many times the film’s screenwriter’s name is mentioned. My gut tells me that the writer’s name is three-to-four times more likely to be mentioned in a negative review than a positive one. But I’d love to see data.

In the meantime, screenwriting will continue to be the most transparent and opaque part of moviemaking.