Sudoku strategy
Habit work on a live board — keep candidates honest, take every single, then look for pairs. Hints name the technique so you can spot the same pattern yourself next time.
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Sudoku strategy
Good sudoku looks dull from the outside: keep candidates honest, take every single, and only then look for pairs or pointing. This page is habit work with a live grid, not a forty-page technique encyclopedia (deeper named moves like X-Wing get their own URL later).
Hints on the board try to speak the same language — technique label plus a short reason. Treat them as coaching, not scripture.
When
When to use
You stall on medium/hard the same way; you want named moves without a textbook; you searched sudoku strategy / how to solve.
When not
When not to
You still need basic rules → how to play sudoku. You want a brutal seed now → evil or hard sudoku. You want cages → killer sudoku.
Defaults
Assumptions
Advice targets classic 9×9. Order of operations beats trivia collecting. Random hard seeds may need techniques beyond this page’s core set — that is fine; grow into them.
Steps
How
- Maintain candidates (pencil) for empty cells you care about.
- Loop naked singles and hidden singles until none remain.
- Look for naked pairs / locked candidates before guessing.
- Stuck → Hint; read the name; find the pattern on the grid yourself next time.
Worked notes
Examples
- A row’s candidates for digit 9 only appear in one box → strip 9 from the rest of that box (pointing)
- Two cells in a column only contain {2,5} → remove 2 and 5 from other cells in that column
Watch-outs
Gotchas
- Collecting technique names without clean candidates is cosplay.
- Guessing “to see” on unique-solution puzzles often forces ugly backtracks — undo your pride, not the logic.
- Strategy blogs without a board are easy to skim and hard to feel; practice above.
Nearby pages
Compare
Rules: how to playApply on hard: hard sudokuApply on evil: evil sudokuKiller sums: killer sudoku
Controls
Quick controls
- Hint — a cell/digit, technique name, and short reason.
- Check — flags conflicts without revealing the full grid.
- Pencil — candidate notes for empty cells.
- New puzzle — same difficulty band, fresh seed.
- Daily — fixed local seed for the calendar day.
- Erase — clear the selected cell (not givens).
FAQ
Common questions
What should I learn first?
Singles, then pairs, then pointing/box-line.
Do hints use real technique names?
That is the point of this product.
Is guessing ever OK?
Rarely; prefer logic.
X-Wing / Swordfish?
Later X-Wing page (batch 3); not required for every hard grid.