You Won't Believe This Chess-Themed Puzzle
This isn't like any chess puzzle you've ever seen.

You Won't Believe This Chess-Themed Puzzle‎

105 | Fun & Trivia

Most chess players can find beauty in chess puzzles, especially ones with clever tricks in the solution.

Check out this thrilling puzzle from our 2019 holiday quiz.

White to play and win:

That puzzle was tough, especially if you didn't catch the critical theme right away. But this next chess puzzle is not a chess puzzle at all.

Recently a video has been making the rounds in the gaming and math circles of the internet, and many who've watched it are shocked the puzzle is solvable with its stark and minimalist starting point.

chess sudoku puzzle
The puzzle's sparse starting conditions seem to make it impossible. Photo: Screenshot from Cracking the Cryptic YouTube video.

It's a sudoku puzzle with some constraints based on chess rules.

If you're not familiar with sudoku, here are the rules:

  • Solvers must place the digits 1-9 in each column, row and box.
  • No digit may share a column, row or box with the same digit.
  • There must be a unique solution that can be achieved through logic alone (no guesswork or trial-and-error required).

To these standard conditions, the puzzle-maker Mitchell Lee has added two more restrictions that will make chess players feel right at home:

  • Any two cells separated by a knight's move or a king's move can't contain the same digit.
  • Any two orthogonally adjacent cells can't contain consecutive digits. (This applies to cells connected vertically or horizontally.)

The expert solver is Simon Anthony, who quit his job at an investment bank to solve sudoku puzzles on YouTube.

He is initially flummoxed at the seeming inscrutability of the puzzle and believes he is being trolled by his YouTube partner. He even mentions stopping the video and calling his friend to berate him for the "impossible" challenge.

It's about this time we realize the old adage is true: There is nothing more exciting than watching a man solve a sudoku puzzle in real time.

The turning point could not have been scripted any better. The solver realizes the power of the chess-based rules and blurts out, "having said that," before getting started on the solution.

The rest of the video, which is absolutely worth watching for its full 25-minute runtime, becomes less about the mechanics of the puzzle and more about the solver's appreciation for the puzzle-maker's genius. The chess-based rules actually empower the solution to the minimalist starting puzzle.

The solver's YouTube channel, called "Cracking the Cryptic," has more of these sudoku puzzles with chess restrictions if you want to go down that rabbit hole. Here's another enjoyable real-time solving video of a chess-based sudoku.

If you'd rather stick to more traditional puzzles, many are available on, including the quite addictive Puzzle Rush.

Give them a try, and let us know your favorite chess puzzles in the comments.

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