The History of Peg Solitaire
A single-player puzzle old enough to have its own court legend, and the subject of one of the more surprising results in recreational mathematics.
A French Court Game
The earliest confirmed evidence of peg solitaire comes from late-17th-century France, where the game appears in a 1697 engraving and was fashionable enough at the court of Louis XIV to be mentioned in contemporary writing. A popular legend credits its invention to a nobleman confined alone on an island - a charming story with no supporting evidence, and almost certainly invented well after the fact to give the game a more romantic origin.
The board that became standard in France has 37 holes (adding four more corners to the plain cross), while the version that spread to England - the 33-hole cross used here - became the more common English-language standard, popularized in Britain during the 19th century.
One Board, Many Shapes
Beyond the classic cross, solitaire boards have been built in triangular form (with its own 15-peg version, a fixture of American restaurant tables for decades), diamond shapes, and other arrangements - the jumping rule stays identical no matter what shape the holes are arranged into.
Because every move removes exactly one peg, a full game from n pegs to 1 always takes exactly n-1 jumps - one of the few board games where the move count of a won game is fixed in advance, regardless of which particular sequence of jumps gets there.
A Solved Puzzle, With a Twist
Peg solitaire attracted serious mathematical attention starting in the 1960s and 70s, when researchers including John Conway analyzed it using tools like resistor-network and group-theoretic arguments to work out exactly which final single-peg positions are reachable from the standard starting position - the center is one of them, though far from the only one.
Later computer search settled the question completely for the 33-hole board: a game starting with the center empty can always be finished down to one peg, and the number of essentially different winning games has been computed exactly - a rare case of a physical puzzle turning into a fully solved combinatorial problem.