Through these 2,800 considerations, Jockers, Archer and Tusker have created a model that gives an aggregate score to a book or author based on the likelihood of being a New York Times best-seller. Most best-selling books scored better than 90 percent. The model gave J.K. Rowling a 95 percent. John Grisham got a 94 percent. James Patterson got a 99.9 percent.

The machine’s greatest achievement might be explaining why E.L. James’ “Fifty Shades of Grey” became — as Jockers and Archer put it — “literary cocaine to millions of readers.”

Jockers and Archer thought it might be the book that broke the machine. Yet the machine discovered something unique to “Fifty Shades,” and it had nothing to do with sex: The book has perfect curves.

One of the best-seller-ometer’s tricks is to mine the text and measure the ups and downs of its sentiment. Imagine a graph that charts the conflicts and resolutions across a whole plot. The conflicts look like valleys, and resolutions look like peaks. A book with good curves means that lots of exciting stuff happens and at a good pace. The greater the frequency and regularity of the waves, the more likely readers will enjoy the book and turn it into a best-seller.