Sudoku Sova

Sudoku technique · First needed at: Fiendish

XYZ-Wing

One of these three cells must hold this number, so nothing seeing all three can.

An example from a real puzzle

3479474674567928591147953473479836234626813459459759347252336135691569123548484586347214579133791234834574572353623674684892146831675532791678167416826468271546784672363689
  • The cells that make the pattern
  • Candidates it removes

How to spot it

  1. Find a pivot cell with three candidates: X, Y and Z.
  2. Find two cells it sees: one with X and Z, one with Y and Z.
  3. A cell that sees all three cannot be Z.

Why it works

Whatever the pivot takes, one of the three cells ends up as Z, and a cell seeing all three would clash with it.

Sova teaches XYZ-Wing inside the game — and gives you puzzles to practise it on. Free on iPhone and iPad.

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