73
62
71
54
65
67
52
75
52
79

Tap a square to see where the knight could step next.

No numbers. Ten sums. One answer.

A hidden knight's tour numbers every square. The margins print the sum of each row and column. Restore the tour.

A puzzle with a proof

Every board is certified to have exactly one solution. The Sunday empty grid is possible because a tour and its reverse only share sums when the tour is semi-magic.

Any board

  • Flat
  • Torus
  • Cube
  • Möbius
  • Hex
  • Goban 19×19

From Beverley to Funk

  1. 1848 — Beverley's semi-magic tour: a property.
  2. 2026 — Funk turns the sums into a clue.
  3. Today — a certified genre, one answer per board.