Sudoku Strategies & Techniques Guide
Master solving techniques from beginner Naked Singles to master X-Wing patterns.
Naked Single Technique (ε―δ½θ§£ζ³)
A Naked Single occurs when 8 out of 9 numbers are already present in the intersecting row, column, and 3Γ3 box of a specific cell. By process of elimination, the remaining number must be the solution.
Hidden Single Technique (ιζ§ε―δ½)
A Hidden Single occurs when a particular number has only ONE valid spot remaining within a row, column, or 3Γ3 box, even though other candidate numbers might also fit into that cell.
Naked Pair Technique (ζ°ε―Ήε εζ³)
If two cells in the same row, column, or 3Γ3 box contain only the same two candidate numbers (e.g. {2, 7}), those two numbers must occupy those two cells. Therefore, {2, 7} can be eliminated from all other cells in that unit.
X-Wing Master Technique (X-Wing 解ζ³)
An X-Wing occurs when a specific candidate number appears only twice in two different rows, and these candidates share the exact same two columns (forming a rectangle). You can eliminate that candidate from the rest of both columns.