ARTICLE

X-Wing Technique: Rectangle Elimination Pattern

Master the famous X-Wing technique in Sudoku. Learn how finding candidate rectangle patterns lets you erase candidates with absolute precision.

When basic candidate eliminations no longer yield progress, the X-Wing technique provides an elegant breakthrough.
By spotting a 2x2 rectangle formed by a single candidate digit across two rows, you can safely eliminate that digit from the rest of those two columns.

Conditions for an X-Wing

Focusing on a single digit (e.g., 7), there are exactly 2 possible candidate cells in two separate rows.
These 4 cells align perfectly in the same two columns, forming a rectangle.

X-Wing Diagram

.	7 (X)	.	.	.	.	.	7 (X)	.
.	7	.	.	.	.	.	7	.
.	7 (X)	.	.	.	.	.	7 (X)	.
.	.	.	.	.	.	.	.	.
.	.	.	.	.	.	.	.	.
.	7 (X)	.	.	.	.	.	7 (X)	.
.	7	.	.	.	.	.	7	.
.	7 (X)	.	.	.	.	.	7 (X)	.

Conclusion: Digit 7 CANNOT exist anywhere else along Columns 2 and 8! (Strike-through cells can have candidate 7 removed).

Back to Home