Sudoku techniques · Master
XYZ-Wing in Sudoku
An XYZ-Wing is a Y-Wing with a three-candidate pivot. The pivot holds XYZ, one wing XZ and the other YZ. At least one of the three cells must be Z, so any cell that sees all three of them, pivot included, loses Z.
Why it works
At least one of a pivot and its two wings must hold their shared number, so any cell that sees all three loses that candidate.
How to spot it
The extra candidate in the pivot costs you reach: the elimination now has to see three cells, not two.
- In practice that means the whole pattern has to sit in one box, with the two wings on lines through it.
- Start from three-candidate cells, not two: that is the opposite of a Y-Wing hunt.
- Only the shared Z is removed, and usually from just one or two cells.
Builds on
Worked example
These are the app's own lesson boards. Step through them the same way a hint does.
- 1
The pivot cell has exactly three candidates 2, 8 and 5, and it sees two bivalue wings: one with 2 and 5, the other with 8 and 5. This forms an XYZ-Wing!
- 2
Since at least one of the three cells must be 5, we can remove the candidate 5 from any other cell that sees all three.