WXYZ-Wing

Level 8 · Blue Belt

Strategy:

Requires:

Learn after:

Overview

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.

How It Works

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

Example

Look for WXYZ-Wing.

Sudoku grid showing the initial puzzle state for Look for WXYZ-Wing.

1

WXYZ-Wing

Find a pivot cell r2c5 with candidates connected to a 3-cell wing group.

Sudoku grid illustrating step 1: WXYZ-Wing — Find a pivot cell r2c5 with candidates connected to a 3-cell wing group.

2

WXYZ-Wing

The wing cells r3c4, r3c7 and r3c9 form an Almost Locked Set with the pivot.

Sudoku grid illustrating step 2: WXYZ-Wing — The wing cells r3c4, r3c7 and r3c9 form an Almost Locked Set with the pivot.

3

WXYZ-Wing

This is a WXYZ-Wing - the shared candidate is eliminated from common peers.

Sudoku grid illustrating step 3: WXYZ-Wing — This is a WXYZ-Wing - the shared candidate is eliminated from common peers.

4

WXYZ-Wing

One of the four cells must contain 3, so eliminate from cells seeing all four: r2c9.

Sudoku grid illustrating step 4: WXYZ-Wing — One of the four cells must contain 3, so eliminate from cells seeing all four: r2c9.

5

Result after applying the technique.

Sudoku grid showing the result after applying the technique

Tips & Patterns

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