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Y-Wing

Another name for the XY-Wing — a three-cell bi-value hinge that removes a shared candidate.

Y-Wing is the traditional name for the pattern also called XY-Wing. A pivot cell {X,Y} links two wing cells {X,Z} and {Y,Z}; because one wing is always forced to Z, the digit Z is eliminated from any cell seeing both wings.

If you have learned the XY-Wing you already know the Y-Wing — the article is kept distinct because both names are widely searched.

How to spot it

The hunt is identical to the XY-Wing: locate a bi-value pivot and two bi-value wings that share the elimination digit Z. The three candidates X, Y, Z chain through the cells like the arms of a Y.

  • Three bi-value cells sharing digits in a Y.
  • Pivot connects both wings, which share Z.
  • Remove Z where both wings are seen.
The hinge forces a 9 into one wing — cells seeing both wings lose theirs.

Worked example

  1. Pivot {2,6} sees wing {2,9} and wing {6,9}.
  2. Pivot = 2 forces the first wing to 9.
  3. Pivot = 6 forces the second wing to 9.
  4. So a 9 lands in one wing for sure.
  5. Cells seeing both wings cannot be 9 — eliminate it.

Try it yourself

5
7
1
4
8
2
1
9
5
4
6
1
2
3
4
7
9
8
3
7
8
8
5
6
3

Tap a cell, then a number, to practise.

Frequently asked questions

Is Y-Wing different from XY-Wing?
No, they describe the same three-cell pattern. The names are interchangeable.
What about XYZ-Wing?
XYZ-Wing is an extension where the pivot has three candidates {X,Y,Z}; the elimination logic is similar but tighter.

Related techniques

Practice: Y-Wing

Put the Y-Wing to work on a live board — free puzzles with notes, hints and four difficulty levels.

Try it on a live board

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