Most advanced and professional players know about the X Wing strategy. However, lesser-level players often overlook it or do not fully understand it. The X Wing strategy is governor of poker among the simplest yet effective Sudoku rules. Its occurrence is usually quite low at these levels, but its purpose is still the same: to eliminate contenders.
When looking at a sudoku grid, there are two directions to check. Either the x-ray or the search option must be used depending on the level of play. In the case of beginner levels, the player should always start with the freecell solitaire search option. The player can then use this strategy when a candidate has been eliminated in four vertical cells which form either a triangle or a square when connected horizontally by a column and row.
There are no restrictions on the numbers of rows and columns. As long as the sum of all the squares in a column and the sum of all the squares in a quadrant is equal to the maximum number of candidates allowed in that column or quadrant, the candidate will still be visible. If the player is stuck on a single V diagonal, she can always use the search option. At higher levels, though, the possibilities for finding the hidden V are limited, and for that, additional search strategies must be used.
