Intersections
One candidate stays inside a shared row, column, or block.
Personal practice for the patterns that stop you
Practice what stopped you.
Replay a difficult position, recover its reasoning, and choose a focused technique search from the candidates instead of guessing.
Screenshot, photo, or typed grid · Answer hiddenRead the signals before choosing.
Choose the cheapest promising search.
The simple pass is complete. Which candidate shape gives the clearest starting objects?
- 01Read the signals before choosing.
- 02Choose the cheapest promising search.
- 03Check every peer of one possible pivot.
- 04Progress resets the search order.
Which method family deserves the first search?
Two-candidate links. The linked two-candidate cells give a finite list of possible pivots. A method search ends only after every valid start is checked.
From a difficult move to a reusable method
Recover the reasoning, not the answer.
When a move goes wrong, I’ll save the position here so you can solve it again later.
- 01
Find where to look
Rebuild one saved proof. Tap a cell where it supports a move.
- 02
Show what proves it
Tap one cell that belongs to this saved proof.
- 03
Make the move
Choose the number or candidate that the proof supports.
- 04
Use again
Use the pattern on a changed board without a pattern marked for you.
Read the board before searching
How to choose the next technique
A stalled grid does not tell you to search every advanced technique at random. Read the notes first. Their shape tells you which kind of search is cheap and plausible.
Read the candidate shapes before naming a method.
Candidate sets
Two or three cells restrict a small set of digits inside one unit.
Digit maps
One digit repeats in a small set of rows and columns.
Two-candidate links
Several two-candidate cells see one another and share values.
Choose from the notes, then finish the search.
Intersections suggest locked candidates. Small candidate sets suggest pairs or triples. Repeated positions for one digit suggest fish. Connected two-candidate cells suggest wings. For any method, inspect every valid starting object before deciding that its search found nothing.
Turn two-candidate cells into a bounded wing search
List the possible pivots, check each pivot’s peers for both matching wings, and stop only when a wing is proved or every pivot has been rejected.
- Read the candidate shapes before naming a method.
- Choose the method family with the clearest starting objects.
- Check every valid start, then either use the proof or move on.
- After any elimination, return to scanning and singles.
Read the board’s signals, choose a bounded search, check every valid start, and restart with simple methods whenever the grid changes.
Continue with the right next step
Sudoku hints without spoilersStart with where to look, then the reason, and only finally the digit.Technique libraryFollow the public guides in order, from scanning to candidate patterns.Bring your own SudokuUse a screenshot, photo, or typed grid and ask for the next logical move.Interactive lessonsPractice the method on fresh boards with immediate feedback.Keep the proof boundary visible
Advanced techniques are learned inside the complete lesson.
The public hub explains the practice loop and the signals to inspect. The complete proof, near-miss checks, guided exercise, and feedback stay inside Coaching.