Why a knight's tour?
Every October, on the second Saturday, the United States marks National Chess Day — a day first proclaimed by President Gerald Ford in 1976. For 2026 that is 10 October. Instead of a chess engine or a news page, we built the oldest, purest chess puzzle there is: move a knight so it visits every square exactly once.
It needs no opponent and no prior chess knowledge, yet it is genuinely hard, endlessly replayable, and more than a thousand years old. It is also a real piece of mathematics — the Hamiltonian path problem in disguise — with a history that runs from Sanskrit poetry to Deep Blue.
What's inside
🎮 The game
Four modes — Tour, Rush, Path and a 20-level Campaign — with a Warnsdorff hint solver, undo, timers, saved bests and shareable challenge links.
📚 Learn
How the knight moves, the strategy behind Warnsdorff's rule, and the exact mathematics of when tours exist and how many there are.
🕰️ History
A timeline from chaturanga and Rudrata's poem to Euler, the Turk, Perec and the modern online chess boom.
🧠 Quiz
Thirty-two questions that take you from Beginner to Grandmaster, with an explanation after every answer.
How it was built
Knight's Gauntlet is a single static site — plain HTML, CSS and JavaScript with no backend, no trackers and no accounts. The board, the knight logic, the hints and the path scoring all run in your browser.
- Hints use Warnsdorff's rule (always move toward the square with the fewest onward moves) backed by a bounded depth-first search, so a hint is only offered when a route really exists.
- Path mode scores you against a true breadth-first-search optimum, so a perfect score is always possible.
- Progress — best times, high scores, campaign stars and your theme — is saved in your browser's local storage, and the site still works if storage is unavailable.
- Sharing encodes the challenge into the link (for example
?r=…), so the person who opens it gets the same starting square. - No images are required: the board, the logo and the knight are all drawn with CSS and SVG.
Sources
Facts and numbers on this site were drawn from the following references.
- Wikipedia — Knight's tour (history, existence conditions, tour counts, Warnsdorff's rule)
- Wikipedia — Knight (chess) (movement, value, names in other languages, Stamma's mate)
- Wikipedia — History of chess (chaturanga, shatranj, world champions, computers)
- DaysOfTheYear — National Chess Day (date, Gerald Ford, fun facts)
- Chess.com — National Chess Day (second-Saturday observance, 1976 proclamation)
- OEIS A165134 (number of knight's tours on an n×n board)
Knight's Gauntlet is an independent, non-commercial project and is not affiliated with any chess organisation. Content is original; no third-party art or code is bundled.