WXYZ-Wing
Extreme
Used by Smart Hint
XYZ-Wing stretched to four cells: a pivot plus three wings whose combined candidates match the pivot's exactly.
- Cells that establish the pattern
- Where the conclusion lands
- Candidate ruled out
How it works
- A1 is the pivot with candidates {1, 2, 3, 4}. B1, A2, and A3 are three bivalue wings, each a peer of A1, and together their candidates {1,4}, {2,4}, {3,4} combine to exactly A1's four candidates.
- Digit 4 is common to all three wings. Whatever A1 turns out to be, either A1 itself is 4, or the one wing that shares A1's actual value is forced to 4 instead — so 4 always lands somewhere among these four cells.
- B2 sees every cell that could hold that 4 (A1, B1, and A2), so its own candidate 4 can be eliminated.