The other week my parents, whom I were visiting, were watching some TV-series, and I saw a couple of minutes towards the beginning. I then guessed who would be shot and how it would end. I was 100% correct, without having any more information than those few minutes. That wasn't because the TV-series was in itself predictable, but because I made a split second calculation about what to me seemed the most plausible outcome, based on a variety of different facts and hunches. But had it ended completely differently, I wouldn't have been surprised (only less pleased with myself...).
In what is often called "art cinema" or "non-classical cinema" (nonsensical terms), unpredictability is sometimes seen as a given, but the same rules applies here. A couple of examples that spring to mind are The Idiots (Idioterne 1998), where after a few minutes I correctly guessed why the main character was doing what she was doing, It's Voltaire's Fault (La faute à Voltaire 2000), where I pictured the last scene before me after a few minutes, and the same thing happened when I saw Shortbus (2006). (Which isn't to say I didn't like the films.) But if a film bores me, this is a little game I play. For example, when I saw Beyond (Svinalängorna 2010) I guessed who would die, when a car would drive off the road, when the music would come in, and so on, and I was never wrong.
With these films, it's not that their stories were predictable, but again, as with that TV-series, I just made informed guesses based on a lifetime of watching films, reading books and observing people. And I suppose it is the same with most people when they're watching a film. Whether or not we find a film predictable depends on how knowledgeable we are, and how good we are at reading the signs in the films. Because there are almost always signs, put there by the filmmakers, sometimes consciously, sometimes unconsciously.
A question though is what we mean when we say that a film is predictable. How much of what is happening in the film must we be able to guess in advance for it to be deemed predictable? Just the ending, or every action taken in the course of the plot, or does it differ from film to film? Perhaps we should say that there are different levels of predictability. The path of the main characters might be easy to guess, but not for the side characters. Or we might be able to guess how something will end, but not why.
But, it could be argued that no film is predictable until after you've seen it. Not in the sense that all films will surprise you, but that you never know beforehand whether it will surprise you or not. Take such a formulaic genre as romcoms. In most cases they end happily for the couple involved. But quite a few ends with the couple going their separate ways, and if you've seen anyone if these, it should be enough to keep you in suspense. Maybe this particular film you're watching now is one of those that will not end with a harmonious union.
Most romcoms of course will end well, whereas other genres are consistently unpredictable. Westerns, horror films and science fiction films all have their individual rules and regulations, but how they will end is not set in stone. It might end tragically or happily, or it might be an open ending. But if you pay attention when watching, you might guess, based on the mood and atmosphere in the film. But you will never know, not until the last shot. Or, in some cases, not even then.
(Warren Oates and Monte Hellman, a match made in heaven.)