A field course in proven moves
Sudoku technique coach
Five short lessons turn candidate marks into evidence you can recognize on a real grid.
No score, leaderboard, or permanent mastery claim. Practice evidence stays on this device.
Your local field notes
0 / 5
Evidence recorded after three consecutive correct exercises. It is a practice marker, not a permanent claim of mastery.
Recommended next lesson- 01Open lesson
Naked Single
Not startedOne empty cell has only one legal candidate.
Reading local evidence…
- 02Open lesson
Hidden Single
Not startedA digit has only one possible cell inside a row, column, or box.
Reading local evidence…
- 03Open lesson
Locked Candidates
Not startedCandidates confined to one line inside a box eliminate that digit farther along the line.
Reading local evidence…
- 04Open lesson
Naked Pair
Not startedTwo cells in one unit share the same two candidates, reserving both digits.
Reading local evidence…
- 05Open lesson
X-Wing
Not startedTwo matching candidate pairs across two rows or columns lock a digit into four corners.
Reading local evidence…