How to Improve at Sudoku

The Plateau

Every Sudoku player hits a plateau. You breeze through easy and medium puzzles, but the moment you try a "Hard" puzzle, you stare at the screen for twenty minutes without placing a single number. Improving at Sudoku is less about learning complex mathematical formulas, and more about training your eyes and memory.

1. The "No-Notes" Training Regiment

The single best way to improve your speed is to play "Medium" difficulty puzzles without ever clicking the Notes (Pencil Marks) button.

By forcing yourself to solve without notes, you are actively training your working short-term memory. You must hold the state of the board in your head. Initially, this will be frustrating, and your times will be slower. But after a week of "No-Notes" training, you will find that your visual processing speed has doubled.

2. Master the "Snyder Notation"

When you do move on to Hard or Expert puzzles where notes are mandatory, you must use notes efficiently. Amateurs fill every empty cell with every possible candidate (1 through 9), which creates visual chaos.

Grandmasters use Snyder Notation. The rule is simple: You only place a pencil mark if a number is restricted to exactly TWO cells within a 3x3 box. If a number can go in three or four cells, do not write it down. This keeps the board clean and makes spotting Naked Pairs incredibly easy.

3. Post-Match Analysis

When you finish a puzzle, do not immediately close the tab. Look at the completed grid. Identify the sections where you got stuck. Was there a hidden pair you missed? Was there an obvious cross-hatch you overlooked because you were hyper-focused on a different corner of the board? Reviewing your own matches is the fastest path to recognizing your blind spots.