Naked Pairs
Naked Pairs is an elegant technique where two cells in the same row, column, or box contain the same two candidates, allowing you to eliminate these candidates from other cells.
Intermediate
What are Naked Pairs?
A Naked Pair occurs when two cells in the same group (row, column, or 3x3 box) have exactly the same two candidates and no others. Because the two numbers must go in these two cells, you can eliminate them from all other cells in that group.
How to Identify Naked Pairs
- Find two cells in the same row, column, or box with exactly the same two candidates
- Verify that both cells have no other candidates
- Remove these two candidates from all other cells in the same group
Example
In a row, two cells both have only {2,7} as candidates. The 2 and 7 must then go in these two cells. You can safely remove 2 and 7 as candidates from all other cells in that row.
Pro Tips
- Naked Pairs are common and relatively easy to spot with good notation
- Don't forget to check in boxes, not just rows and columns