Pencil Marks Done Right: Clean Notes for Faster Solves
Pencil marks (candidate notes) turn a blank cell into a shortlist. Used well, they make Hidden Singles and Naked Pairs obvious. Used poorly, they bury the board under stale digits and slow you down. The goal is not to fill every empty cell with 1–9 — it is to keep a honest shortlist that updates after every move.
Notes are a map. Out-of-date maps get you lost.
What good pencil marks look like
A good note set answers one question: which digits are still possible here? On Sudoku Hot, Notes mode lets you tap candidates in and out without cluttering the big digit. Prefer light marking — only mark cells you are actively studying, or only mark digits that already feel constrained. Full-board "fill every candidate" works for some advanced techniques, but beginners often benefit from selective notes that highlight the next elimination.
A clean notes workflow
- Place obvious singles first. Fill Naked and Hidden Singles before flooding the grid with notes. Notes should support logic, not replace a basic scan.
- Mark only what you need. When stuck on a house, add candidates for that house. Avoid writing nine digits in every empty cell "just in case."
- Update notes after every placement. The moment a digit lands, erase it from peers in its row, column, and box. Stale candidates create false pairs and fake X-Wings.
- Use Notes mode as a mode, not a lifestyle. Toggle Notes on to edit candidates, then toggle off to place big digits. That mental switch keeps the board readable on phone and desktop.
Practice this workflow on Easy and Medium grids until updating notes feels automatic. Then take the same discipline into Hard, Expert, and Hell Mode — clean candidates are what make advanced patterns visible.
