The History of Mastermind
A code-breaking game of pure logic, with no rival player to outwit, that grew out of a much older pencil-and-paper guessing game and went on to become a favorite subject for computer scientists studying how to search for a hidden answer efficiently.
From Bulls and Cows to a Board Game
Mastermind's central mechanic - guess a hidden code and get back only a count of exact and partial matches, never which positions are right - comes from Bulls and Cows, a much older pencil-and-paper (and later computer) guessing game traditionally played with secret numbers instead of shapes or colors.
In 1970, Mordecai Meirowitz, an Israeli postmaster and telecommunications expert, adapted that idea into a physical board game played with colored pegs. After the concept was turned down by several major toy companies, the British firm Invicta Plastics licensed it and brought it to market that same year under the name Mastermind.
A Best-Seller
Invicta's Mastermind became one of the best-selling games of the 1970s and 1980s, eventually selling tens of millions of sets worldwide and spawning travel editions, a numbers-only variant, and a long-running series of sequels and spin-offs.
A Favorite Puzzle for Computer Scientists
Because it boils down to searching for a hidden answer using nothing but match-count feedback, Mastermind became a standard test case in computer science and combinatorics for studying guessing strategies and search algorithms, well beyond its life as a party game.
In a well-known 1977 paper, "The Computer as Master Mind", Donald Knuth showed that the classic four-peg, six-shape version can always be solved in at most five guesses using an optimal strategy - a result still cited whenever the game comes up in discussions of algorithmic search.