Answer: Jazz

The game of Hangman, for the unfamiliar, is a simple word game in which the audience (typically school children) is presented with a series of blanks to represent the unknown letters of a word. Every correct guess results in that letter being filled in, but every incorrect guess results in the game master drawing part of a stick figure hanging from a noose. In a typical game, the game master draws the head, the body, and the limbs—six wrong guesses completes the hanging and the players lose.

Mathematician Jon McLoone was curious about the outcome of the simple game. What is the most fiendishly difficult word to guess in a game of hangman? He created a computer simulation to run through 50 trials of the game using 90,000 English words, with the simulation using the same basic strategy as a human player: pick vowels, then pick common letters.

The end result? Jazz proved to be the most difficult word to guess since it’s short, has a common vowel in the center, but is framed by two uncommon letters: J and Z. Even with over a dozen chances to solve for the puzzle, when confronted with “jazz”, the computer would fail. Conversely, McLoone found that, rather ironically, “difficult” was one of the easiest words due to its double vowels and multiple common letters.