Hard Used from hard puzzles up.
XYZ-Wing
A three-candidate pivot
Like the XY-Wing, but the pivot has three candidates, X, Y and Z, and the wings are X Z and Y Z.
Whatever the pivot holds, Z is in the pivot or in one of the wings.
So a cell that sees all three of them cannot be Z: remove it there.
What to look for
Find a three-candidate cell that sees two two-candidate cells, the three sharing one digit.
Example
- The cells the technique relies on
- Cells where it removes candidates, struck out in red
Practise it
In the app, Learn › XYZ-Wing sets exercises on real positions, then a full puzzle that needs this technique and nothing harder.