WXYZ-Wing

WXYZ-Wing uses four cells with candidates forming a restricted pattern. When properly configured, a common candidate can be eliminated from cells seeing all pattern cells.

Technique

1. Find four cells whose combined candidates use exactly four digits {W,X,Y,Z}.
2. One cell (pivot) sees the other three.
3. Eliminate the restricted digit from cells seeing all four pattern cells.

Tips

• WXYZ-Wings have complex requirements - study examples carefully.
• They extend the Wing family pattern to four cells.
• These are quite rare in most puzzles.