XY-Wing
Expert
Used by Smart Hint
A pivot cell and two "wing" cells, each sharing one candidate with the pivot, corner a shared digit out of any cell both wings can see.
- Cells that establish the pattern
- Where the conclusion lands
- Candidate ruled out
How it works
- A1 is the pivot with candidates {1, 2}. E1 shares its row and candidate 1 (plus a 3); A5 shares its column and candidate 2 (plus that same 3).
- If A1 is 1, E1 can't be 1, so it must be 3. If A1 is 2, A5 can't be 2, so it must be 3. Either way, one of the wings is 3 — eliminate 3 from E5, which both wings can see.