In 1999, the American Crossword Puzzle Tournament included an unhuman (and thereby unofficial) contestant. After New York Times crossword editor Will Shortz wrote an essay alleging that it would be impossible for a computer to compete with humans at solving crosswords, a group of computer scientists took his words as a challenge. Before long, a group from Duke University developed Proverb—the name is derived from “probabilistic cruciverbalist”—a program capable of solving American-style crosswords using probability theory.
After hearing that Proverb could ascertain about 90% of the answers to New York Times crosswords, Shortz invited the computer to try the tournament puzzles. Although Proverb finished 20th on one puzzle and placed a respectable 147th out of 254 contestants overall, its results were skewed downward by finishing 251st on a puzzle in which every clue involved a spoonerism—when you interchange consonant sounds in a phrase in order to make a new phrase. For example, ‘May I sew you to a sheet’ is a spoonerism on ‘May I show you to a seat.’ While acknowledging that Proverb performed surprisingly well, Shortz laughed and said, “The puzzle with the spoonerisms killed it. It had none of that stuff in its database and the computer couldn’t figure out the gimmick.” Unlike Garry Kasparov, it seems that 2001 American Crossword Puzzle champion Ellen Ripstein has nothing to fear.