Finned X-Wing

A Finned X-Wing is an X-Wing pattern that has one or more extra candidates (called "fins") in one of the defining rows or columns.

Pattern Recognition

A Finned X-Wing has:

• A standard X-Wing pattern (candidate in exactly two positions in two rows/columns)
• One or more extra candidates ("fins") in one of the base rows/columns
• The fins are confined to a single box that also contains one corner of the X-Wing

How It Works

The fin restricts where eliminations can occur. If the X-Wing is valid, eliminations happen as normal. If a fin is true instead, the elimination cell would still see the fin. Therefore, any cell that sees both a corner of the X-Wing and all the fins can have the candidate eliminated.

Example

Documentation stub - examples coming soon.

Related Techniques

• X-Wing — The base fish pattern
• Swordfish — Three-row/column fish
• Finned Swordfish — Swordfish with fins