Sudoku FlowSudoku technique lessons / Y-Wing
Lesson 16
Y-Wing
The rule
A pivot forces at least one of its two wings to hold their shared number, so any cell that sees both wings loses that candidate.
Step by step
- The pivot is a bivalue cell with 3 and 7, and it sees two bivalue wings: one with 3 and 5, the other with 7 and 5. This forms a Y-Wing!
- Since at least one of the two wings must be 5, we can remove the candidate 5 from any other cell that sees both wings.
Try it on more boards
Each board is a real puzzle from our app, at a moment where Y-Wing applies. Find the step yourself, or tap Hint and the app's own hint walks you through it.
Want more boards like this?
We also make a Sudoku app for iPhone, iPad, Mac and Android. There are no ads in it at all, it works offline, and when you ask for a hint it shows you the technique instead of just filling in a number.
Sudoku Flow is made by Rubigo Games, the developer of the Sudoku app recommended on this site.