Sudoku solving technique · Pro
XYZ-Wing
Like a Y-Wing, but the hinge has three candidates.
What is an XYZ-Wing?
An XYZ-Wing works like a Y-Wing, but the hinge has exactly three candidates. It sees two wing cells with exactly two candidates each. All three cells share one candidate, and each wing also holds a different one of the hinge's other two. The shared candidate can be eliminated only from cells that see the hinge and both wings.
How to spot an XYZ-Wing
Look for a hinge with exactly three candidates, say 1, 2 and 3, that sees two wings with two candidates each, say 1 and 3, and 2 and 3. All three cells share 3. Because the hinge itself can also take 3, the digit only leaves cells that see the hinge and both wings, which is usually just one or two cells in the hinge’s box.
- Difficulty
- In Sudoku Pro, this technique belongs to the Pro level.
- Learning path
- Technique 15 of 20 on the learning path
An example from the app
| Given 4 | Given 5 | Empty | Empty | Empty | Empty |
| Given 3 | Pattern (purple). Candidates 1, 6 | Given 2 | Empty | Empty | Empty |
| Empty | Empty | Given 5 | Empty | Empty | Empty |
| Empty | Empty | Empty | Empty | Empty | Empty |
| Empty | Pattern (purple). Candidates 1, 3, 6 | Given 4 | Empty | Given 2 | Empty |
| Empty | Affected cell (orange). Candidates 2, 3. Eliminated 6 | Pattern (purple). Candidates 3, 6 | Given 1 | Empty | Empty |
Small digits are candidates. Crossed-out digits can be removed in this step.
- Pattern (purple)
- Affected cell (orange)