Swordfish Practice Puzzles

A Swordfish is a pattern where a candidate digit, across three rows, is confined to the same three columns. The digit can then be eliminated from every other cell in those three columns. The row and column roles can be swapped.

Every puzzle below is verified to feature the Swordfish as its hardest required technique — of the 65,284 puzzles in our library, 12,015 require it and 12,015 need nothing harder. New to the pattern? Learn the Swordfish or see a worked example first.

Curated Swordfish puzzles

  1. Practice puzzle #1 — 24 givens · needs Naked Single, Swordfish
  2. Practice puzzle #2 — 23 givens · needs Naked Single, Swordfish
  3. Practice puzzle #3 — 26 givens · needs Naked Single, Hidden Single, Swordfish
  4. Practice puzzle #4 — 26 givens · needs Naked Single, Hidden Single, Swordfish
  5. Practice puzzle #5 — 24 givens · needs Naked Single, Hidden Single, Swordfish
  6. Practice puzzle #6 — 24 givens · needs Naked Single, Hidden Single, Swordfish
  7. Practice puzzle #7 — 25 givens · needs Naked Single, Hidden Single, Swordfish
  8. Practice puzzle #8 — 24 givens · needs Naked Single, Hidden Single, Swordfish
  9. Practice puzzle #9 — 25 givens · needs Naked Single, Hidden Single, Swordfish
  10. Practice puzzle #10 — 25 givens · needs Naked Single, Hidden Single, Swordfish
  11. Practice puzzle #11 — 23 givens · needs Naked Single, Hidden Single, Swordfish
  12. Practice puzzle #12 — 25 givens · needs Naked Single, Hidden Single, Swordfish
Get a fresh Swordfish puzzle →

Swordfish practice FAQ

How many Sudoku puzzles require the Swordfish technique?
Of the 65,284 puzzles in the Precision Sudoku library, 12,015 require the Swordfish to solve, and 12,015 can be completed with nothing harder than the Swordfish. Every puzzle is verified by a solver that records the exact techniques needed.
What is the best way to practice the Swordfish?
Play puzzles where the Swordfish is the hardest move required, so every sticking point is an opportunity to apply it. Try it after X-Wing fails. It is the same fish logic one size larger and clears stubborn candidates in hard puzzles.
Can I play a Sudoku puzzle that needs exactly the Swordfish?
Yes. The curated puzzles on this page all feature the Swordfish as their most advanced required technique, and the practice button serves a fresh puzzle from the same verified pool whenever you want another.