Hit a wall on your Sudoku grid? Before resorting to guessing, follow this logical checklist to find overlooked moves and refresh your vision.
Every Sudoku player hits a wall at some point where no obvious move presents itself.
Before resorting to random guessing (which breaks puzzle logic), follow this logical rescue checklist to unlock the grid.
The most common reason for getting stuck is simply overlooking a basic move.
Count how many of each digit (1-9) exist on the board. If any digit appears 8 times, the 9th instance can be placed immediately!
If you recently placed a digit, double-check if you erased that candidate from intersecting rows, columns, and 3x3 blocks. A single leftover note can block you from seeing Naked Pairs or Locked Candidates.
Instead of asking "Where does 1 go?", pick an empty cell with many filled neighbors and ask "What numbers CANNOT go in this cell?"
Often, eliminating 8 numbers leaves a single valid choice (Naked Single).
Staring at the same grid causes cognitive fatigue. A 5-minute break clears mental tunnel vision, letting you spot obvious moves instantly upon return.
