XY-Wing
Three bivalue cells – a hinge and two pincers.
Also known as: Y-Wing, Bent Triple, Hinge and Pincers
Quick Summary
An XY-Wing uses three two-candidate cells: a pivot and two wings. Whichever value the pivot takes, one of the wings is forced to a shared common digit, eliminating it from any cell seeing both wings.
Understanding the XY-Wing Technique
The XY-Wing (often called Y-Wing) is one of the most elegant and common expert techniques. It consists of three cells, each having exactly two candidates. One cell acts as the 'pivot' or 'hinge' holding two candidates (such as 3 and 8). The other two cells are 'pincers' or 'wings' seeing the pivot: one holding 3 and 5, and the other holding 8 and 5. If the pivot is 3, the first wing becomes 5. If the pivot is 8, the second wing becomes 5. In all possible outcomes, at least one wing MUST be 5. Therefore, any cell that sees both wings can never be 5.
Visual Examples
Green cells highlight the XY-Wing pattern, amber cells denote where candidates are affected, and struck-through pencil marks show the eliminations. Use the buttons or arrow keys to browse examples.
How to Spot & Solve a XY-Wing (Step-by-Step Guide)
The complete visual scanning and logical deduction process to execute this technique:
- 1Find a two-candidate pivot cell (for example, with candidates 3 and 8).
- 2Locate two wing cells that each share a house with the pivot: one holding 3 and a new digit 5, and the other holding 8 and 5.
- 3If the pivot is 3, the first wing is forced to be 5.
- 4If the pivot is 8, the second wing is forced to be 5.
- 5In either outcome, at least one of the wings must be 5.
- 6Eliminate candidate 5 from any cell in the grid that has a direct line of sight to both wings.
Common Traps & Mistakes to Avoid
- Choosing wings that do not both see the pivot cell.
- Eliminating the wrong digit: you must eliminate the digit shared by the two wings, not the digits in the pivot.
- Eliminating from cells that only see one of the two wings.
Frequently Asked Questions
Do the two wings have to see each other?
No! The wings only need to see the pivot cell. They do not need to see each other.
Can an XY-Wing be contained within a single 3x3 box?
If all three cells were in one box, they would simply form a Naked Triple. An XY-Wing is powerful because the wings reach outside the box across rows and columns.
Related Solving Techniques
Expand your repertoire by learning prerequisites and advanced counterparts:
Ready to Practice XY-Wing?
Try a puzzle in the Hard tier (Peak Score 51–60), or browse all 25 techniques.