Puzzles
A knight can visit every square on a chessboard exactly once
Can a knight, moving only in its usual L-shape, tour an entire 8x8 chessboard, landing on every square exactly once? Indian and Arabic scholars had explored the pattern for centuries as a curiosity, but nobody had analysed it mathematically.
Reveal the answer
Yes — many such tours exist, including 'closed' tours that end a knight's move from the start, letting the knight loop forever. Leonhard Euler published the first rigorous mathematical analysis of the problem in 1759, showing general methods for constructing and joining knight's paths. The knight's tour is now a classic example of a Hamiltonian path problem in graph theory.