W-Wing
Two cells with the same two candidates, linked by a strong link on one of them, eliminate the other candidate from any cell that sees both.
Use when two cells far apart share the same two candidates and a strong link on one of those digits connects them.
-
Two cells share the pair {2,7}; a strong link on 7 connects their columns.
-
Whichever way the link falls, one of the two cells must be 2, so 2 is removed from any cell that sees both.
- Using two cells whose candidates are not exactly the same pair.
- Forgetting that the strong link must be on one of the two shared digits.
Frequently asked questions
What is a W-Wing?
Two cells with the same two candidates, joined by a strong link on one digit. The other digit is then eliminated from any cell that sees both cells.