XYZ-Wing Sudoku Technique: How to Spot and Use It Step by Step

XYZ-Wing connects a three-candidate pivot {X,Y,Z} to two wings {X,Z} and {Y,Z}. Each wing must see the pivot. A target can lose Z only if it sees the pivot and both wings.

Use it after singles, locked candidates, and simpler pair techniques; it is especially useful on hard puzzles where one precise elimination can open the grid.

XYZ-Wing workflow

1. Find a pivot with exactly three candidates, such as R1C1 with {6,7,8}.
2. Find two peers with exactly {6,7} and {7,8}, such as R1C4 and R2C2. Both see R1C1; the wings need not see each other.
3. Check each pivot choice: 6 forces R1C4 to 7; 8 forces R2C2 to 7; otherwise the pivot itself is 7.
4. Remove 7 only from a separate cell that sees all three pattern cells. R1C2 sees the pivot and R1C4 in row 1, and R2C2 in box 1.

Common mistakes to avoid

• Checking only the two wings: the target must also see the pivot, because the pivot may itself contain Z.
• Using wings with extra candidates: the two wings must have exactly the required two-candidate sets.
• Eliminating inside the pattern cells instead of outside them.

FAQ

When should I use XYZ-Wing in Sudoku?

Use XYZ-Wing after singles, locked candidates, and simpler pair/triple techniques are exhausted on hard or expert puzzles.

Is XYZ-Wing just a bigger X-Wing?

No. X-Wing is a one-digit fish across two base lines and two cover lines. XYZ-Wing uses three digits in a pivot and two wings. A size-three fish is a Swordfish.