Expert printable sudoku
Combine box and line information. If every candidate for a digit within a box lies in the same row, that digit cannot appear elsewhere in that row outside the box.
Ready to print 4 printables
Levels
- Expert
- Swordfish, XYZ-wing and short chains
Try an example
Combine box and line information. If every candidate for a digit within a box lies in the same row, that digit cannot appear elsewhere in that row outside the box. Record which rule justifies each elimination.
What to check
Update candidates whenever a cell changes and revisit earlier deductions if a contradiction appears. The number of given digits alone does not determine the challenge; their relationships matter too.
Write only what you can justify
Compare the row, column and box before entering a digit. If several options remain, note them as small candidates and return later. An entry is confirmed by the board’s rules, not by making a row look neatly ordered.