Naked Pairs in Sudoku
Naked pairs are often the first technique that shows how candidates interact across a full unit. Two cells sharing the same two candidates create a strict restriction that drives eliminations elsewhere.
Summary
Use pair patterns in rows, columns, and boxes to eliminate candidates and create new singles.
Table of Contents
What this technique is
A naked pair is two cells in one unit containing exactly the same two candidates and no others.
When to use it
Use when notes are established and straightforward singles are becoming rare in medium and hard puzzles.
How it works
Lock the pair digits into those two cells, then remove the same digits from other cells in the same unit.
Step-by-step
- Find two cells in one row/column/box with identical two-candidate sets.
- Confirm no extra candidates exist in those pair cells.
- Eliminate pair digits from other cells in that unit.
Example
If two cells in a row are both {3,8}, remove 3 and 8 from all other cells in that row.
Example
If two cells in one row are {3,8} and {3,8}, then no other cell in that row can contain 3 or 8.
Common Mistakes
- Calling a pair valid when one cell has extra candidates.
- Eliminating candidates outside the affected unit.
- Assuming a pair must produce an immediate placement.
- Not checking follow-up singles after elimination.
Practice Links
FAQ
What is a naked pair?
Two cells in one unit contain the same two candidates and no others.
Is naked pairs a beginner technique?
It is usually considered intermediate because it depends on candidate notes.
What does naked pairs help with?
It removes candidates from nearby cells and often creates direct placements.