W-Wing

W-Wing consists of two identical bi-value cells connected by a strong link on one of their candidates. The other candidate can be eliminated from cells that see both bi-value cells.

Technique

1. Find two bi-value cells with identical candidates {X,Y} that don't see each other.
2. Find a strong link on digit X (or Y) connecting cells that each see one of the bi-value cells.
3. If the strong link is on X, eliminate Y from cells that see both bi-value cells.

Tips

• W-Wings are relatively easy to spot once you know the pattern.
• Look for matching bi-value cells first, then search for connecting strong links.
• The elimination digit is the one NOT involved in the strong link.