Sudoku Tips & Strategies
Whether you're a beginner or already experienced, these tips will help you solve sudoku puzzles faster and more efficiently.
Beginner Tips
1. Start with what you know for sure
Always start with the easiest cells - where only one number is possible. This gives you more information for the rest of the puzzle.
2. Scan systematically
Go through the grid methodically. Start with one number and find all possible positions for it in each block, row, and column.
3. Use pencil notes
Note possible numbers in each cell. This makes patterns visible and prevents you from forgetting possibilities.
Advanced Strategies
Naked Pairs
When two cells in the same row, column, or block have exactly the same two candidates, those numbers can be removed from all other cells in that unit.
Example: If two cells in a row only have 3 and 7 as candidates, then 3 and 7 can be eliminated from all other cells in that row.
Hidden Singles
If a number can only be in one place within a row, column, or block, even if that cell has multiple candidates, then that number must go there.
This is one of the most powerful techniques for medium difficulty puzzles.
Pointing Pairs
If a candidate within a block only appears in one row or column, that candidate can be removed from the rest of that row or column (outside the block).
Box/Line Reduction
If a candidate within a row or column can only appear in one block, that candidate can be removed from the rest of that block.
Expert Techniques
X-Wing
If a candidate appears in exactly two cells in two rows, and these cells are in the same two columns, then that candidate can be removed from all other cells in those columns. Also works in reverse (columns โ rows).
Swordfish
An extension of X-Wing with three rows and three columns. If a candidate appears in at most three cells per row, and these cells are in three shared columns, eliminations can be made.
XY-Wing
A pattern with three bi-value cells (each with exactly two candidates) that are in a specific configuration and allow for eliminations.
General Tips for Faster Solving
- โFocus on one number: Work out all placement possibilities for one number before moving to the next.
- โDouble-check: Prevent wasted time by verifying each placement.
- โRecognize patterns: The more you play, the faster you'll recognize patterns.
- โTake breaks: If you get stuck, take a break. Fresh eyes often see what you missed.