WXYZ-Wing

A WXYZ-Wing is like an XY-Wing and an XYZ-Wing, except it involves a group of four cells, with one cell sharing a unit with the other three


  1. Consider this example
WXYZ-Wing initial illustration

  1. One of these highlighted cells must contain the value 9
WXYZ-Wing - spot the right candidates

  1. That means the value 9 can’t be placed in any cell that sees all the highlighted cells at the same time
WXYZ-Wing applied to a Sudoku grid