Verified by 
What makes a good story? We are all familiar with that particular friend—typically the life of a dinner party—who can fully engage us with a humorous or dramatic tale. We can also imagine prehistoric humans (as well as pre-teen children) gathered around an evening campfire listening to stories of mirth and adventure. Aristotle in The Poetics suggested that a well-formed plot should be structured as a complete tale with a beginning, middle, and end. Characters should develop through recognition or realization, such as Luke Skywalker realizing that Darth Vader is his father. Movies can be viewed as a multisensory form of storytelling. Good ones capture our attention and keep us riveted to the screen as we anticipate what will happen next.
Syd Field was a screenwriting guru who articulated a three-act story arc for movies: Act I, the Set-up, lasts about a quarter of a movie and introduces the characters which provides insights into their nature, goals, and predicament. Act II, Confrontations, is the longest segment, encompassing the middle half of a movie, which sets the protagonist off ("the game's afoot!") and builds tension through a series of challenges and conflicts. Act III, Resolution, leads to the climax with the last scene serving as a final release of tension. Acts are separated by a plot point, which alters the action and "spins it around in another direction" (Fields, 2005, pg 26). Since antiquity this storytelling scheme has been successful in capturing our attention and driving our emotions. In Hollywood movies, it has been followed so rigorously that many consider it excessively formulaic (can a Hollywood action movie end without a final chase scene?).
The film theorist Kirsten Thompson analyzed the story arcs of over a hundred movies and identified another turning point at the midpoint of many movies, which splits Fields' middle act into two segments. This turning point is marked by a dramatic change in the direction of the main character's goals and disposition. For example in Casablanca, Thompson defined the end of her Act II (which she calls The Complicating Action) as the scene where Ilsa tries to explain to a drunken Rick why she didn't meet him at the train station in Paris. Rick ends the scene dejected after cruelly dismissing her story ("Was it Lazlo or were there others in between…or aren't you the kind that tells"). The scene ends with a fade to black at halftime (51 min into the 102 min movie). In Thompson's Act III (Development), characters must deal with a series of obstacles and realizations. In Casablanca, Rick must renounce his bitterness and try to save Ilsa from a desolate life in Morocco. With this four-act structure, each section is of equal length (about 20-30 min) and marked by a prominent turning point. These large-scale descriptions are of course only guidelines, and Thompson has shown that movies may conform to a 3-, 4- or even 5-act structure, often depending on the length of the movie.
The plot of a good movie is much like a rollercoaster ride which starts with anticipation for what is to come, is followed by a series of ups and downs, and ends with a thrilling climax. A movie's rhythmic pacing involves the varying of tempo with stops and starts, questions and answers, and successes and failures. Buck Henry, the screenwriter for The Graduate, said: "If it's just a series of climaxes, you can go crazy. You have to find some way to moderate the tempo so that it's not all one crescendo, or one diminuendo. There have to be changes of pace to give the audience time to stop and start again" (Froug, 1999, pg 209). In this way, the filmmaker flirts with the viewer by concealing and revealing knowledge as the story progresses. There may be a hierarchy of tensions and releases with small-scale predicaments woven into the fabric of larger-scale conflicts and goals.
Cinemetrics, which pertains to statistical analyses of film features, has been used to capture the rhythmic pacing of films. Analyses by Barry Salt and James Cutting have shown both large-scale and small-scale rhythms or waves that can be defined as clusters of short or long durations of camera shots. Shown in the graph below is an analysis by Barry Salt of the duration of each camera shot across the movie Ride Lonesome. These shot durations varied from 2 to over 20 secs, though it is clear that their ordering was not random as there were clusters of rapid shots in succession as well as clusters of long shots. The red line shows a larger-scale averaging of the shot durations which seems to conform to a 3-act segmentation with each act starting with long shot durations (low points) and followed by a cluster (hump) of rapid shots. As the climax approaches, we see a distinct series of very rapid shots with the final shots increasing in duration. James Cutting and colleagues analyzed 150 feature films and showed that "…the sequence of shot lengths in films has a waxing and waning structure…that occurs simultaneously at different scales—that is, fluctuations on the orders of tens of seconds, minutes, tens of minutes, and longer" (Cutting et al., 2013, pg 4).
When we watch a movie, we are not generally conscious of its rhythmic pacing as we tend to get sucked into the story and pay attention to the drama. Yet filmmakers are well aware of the story arc and its rhythmic scheme, though of course not all movies are successful, as much has to "work" with respect to the acting, visuals, and editing—all in the service of telling a good story. By understanding the psychology of movies, we may begin to understand the features of plot structure that draw our attention and keep us engaged emotionally with the characters. Who knows maybe with such knowledge we may all become better storytellers.
