Sudoku techniques: a practical path
Sudoku technique names can sound more complicated than the decisions they describe. This guide starts with confirmed placements, then moves to candidate elimination. Each article explains what to look for, walks through a small original example, and flags the mistake most likely to cause a false deduction.
Learning path
BeginnerNaked single
One empty cell has only one legal candidate. It is the clearest place to begin a scan.
Open guideBeginnerHidden single
A digit has only one possible home in a row, column, or box, even when the cell has other notes.
Open guideIntermediateLocked candidates
A box and a line constrain each other, allowing safe candidate eliminations outside their overlap.
Open guideIntermediateNaked pairs
Two cells reserve the same two digits, so those digits can leave the other cells in that unit.
Open guideUse notes as evidence, not decoration
Write a candidate only after checking its row, column, and 3×3 box. When a confirmed value is placed, rescan all three units. Voku removes related notes automatically, but the logical reason for every placement should still be clear to you.