X-Wing Explained Simply: An Advanced Sudoku Pattern
When singles and pairs stop moving the board, advanced patterns take over. The X-Wing is one of the cleanest: a single digit locked into two rows and two columns forms a rectangle. Once you see the rectangle, you can eliminate that digit from the rest of those columns (or rows). No guessing — just geometry.
If the candidates draw a rectangle, the eliminations write themselves.
What is an X-Wing?
An X-Wing appears when a digit (say 7) can appear in only two cells of row A, and those same two columns are the only places 7 can appear in row B. The four cells sit at the corners of a rectangle. Because each of those rows must place a 7 in one of those two columns, both columns are "spoken for." Therefore any other 7-candidate in those two columns outside the rectangle can be erased. The same pattern works with columns as the base and rows as the fish fins.
How to spot and apply an X-Wing
- Pick a digit that is almost locked. Focus on a number with few remaining placements. Crowded digits hide patterns; sparse digits reveal them.
- Scan for two rows with the same two columns. In candidate notation, look for a digit that marks exactly two cells in a row, then find a second row with the same pair of columns.
- Confirm the rectangle. The four cells must align. If a third column sneaks into either row, it is not an X-Wing yet.
- Eliminate outside the corners. Remove the digit from all other cells in those two columns (or two rows, if you started from columns). Then look for new singles created by the cleanup.
Practice X-Wings on Hard and Expert Classic grids, then carry the same rectangular thinking into Hell Mode cages when candidates line up across boxes. Pattern recognition is a skill — and Sudoku Hot's difficulty ladder is built to train it.
