Slate‘s Christopher Beam and Jeremy Singer-Vine have used a database of post-1985 Rotten Tomatoes ratings to create a search engine called the Hollywood Career-O-Matic. What it basically says about career trajectories (other than re-posting the steady downward slump suffered by M. Night Shyamalan since The Sixth Sense) is that over time directors are more likely to experience critical upswings than actors.

“What does the average Hollywood career look like?,” Beam and Singer-Vine ask. “In the Rotten Tomatoes database, more than 19,000 actors and 2,000 directors had their first film released in 1985 or later. The average actor’s critical reception gets slightly worse over the course of his first few movies, then plateaus. The average score for an actor’s first film is about 55 percent. By his fourth movie, that score slides to about 50 percent, where it hovers for the rest of his career.

“Directors’ careers follow a different trajectory. Like actors, a director’s first movie averages a Tomatometer rating around 55 percent. But the average ratings for the next few movies don’t drop much at all, never falling below 54 percent. Then, between the average director’s seventh and eighth movie, the Tomatometer ratings jump dramatically, from 55 percent to nearly 63 percent. That score stays steady for the average director’s ninth through 11th films and then jumps again to the 80s and 90s for the rest of his career.

“These trends seem to make sense. Most actors have to appear in good movies early in their career. Those who don’t risk being flushed out of the business. Once they’ve established themselves with a good film or two, they can safely make some bad ones. But all in all, they don’t have nearly as much control over film quality as directors do. Directors’ scores spike over time, presumably because only the best ones stick around long enough to make so many films.”

Slate‘s Hollywood Career-o-Matic tool can “map the career of any major actor or director from the last 26 years,” Beam and Siner-Vine explain. “You can also type in more than one name to plot careers side by side. For example, Paul Thomas Anderson vs. Wes Anderson vs. Pamela Anderson. Mouse over the data points to see which movies they represent.” Beam and Singer-Vine have “included only actors and directors who’ve released least five films between 1985 and March of this year, according to the RT data, to filter out thousands of bit-actors you’ve probably never heard of.”