Snyder Notation
A disciplined pencil-marking method that records only hidden-pair candidates inside boxes to find singles faster.
Snyder notation is not a deduction but a note-taking discipline that makes deductions faster. Instead of marking every candidate in every cell, you mark a digit in a box only when it has exactly two possible cells in that box. The resulting sparse grid surfaces hidden singles and pairs almost immediately.
Named after Thomas Snyder, a multiple world Sudoku champion, it is the marking method behind most fast hand-solving.
How to do it
Go box by box and digit by digit. If a digit can go in exactly two cells of the box, pencil it small in both. Ignore digits with three or more candidate cells for now. Two matching marks in a box that also align on a row or column instantly reveal pairs and pointing patterns.
- Mark a digit in a box only when it has two candidate cells.
- Skip digits with three or more options for now.
- Matching marks reveal hidden pairs and pointing pairs.
Worked example
- In a box, digit 2 fits only two cells — mark both.
- Digit 9 also fits only those same two cells — mark both.
- You have found a hidden pair {2,9} with almost no clutter.
- Clear other candidates from those two cells.
- Continue box by box.
Try it yourself
Tap a cell, then a number, to practise.
Frequently asked questions
- Is Snyder notation a solving technique?
- It is a notation discipline that speeds up finding singles, pairs and pointing patterns — the deductions themselves are the standard ones.
- Why not mark every candidate?
- Full marks clutter the grid and slow you down. Snyder keeps only the highest-signal marks until you need more detail.
Related techniques
Practice: Snyder Notation
Put the Snyder Notation to work on a live board — free puzzles with notes, hints and four difficulty levels.
Try it on a live board