Naked Pair
Prerequisites: Hidden Single
Overview
Two cells in a house sharing the same two candidates lock those digits, eliminating them from other cells in the house.
How It Works
If cells A and B in a house both contain only candidates (X, Y), then X and Y must occupy those two cells. No other cell in that house can contain X or Y.
When To Use It
Look for two cells in a row, column, or box that share the same pair of candidates and contain no other candidates.
How To Detect It
Scan for bivalue cells. If two bivalue cells in the same house share identical candidates, they form a naked pair.
Visual Example
Step 1 of 9
What Is a Bivalue Cell?
A bivalue cell has exactly two candidates. When two bivalue cells in the same house share the identical pair of digits, they form a Naked Pair — and those two digits are locked to those two cells.
Practice
A Naked Pair is hiding here. Use it to eliminate, then fill the cell that becomes a Naked Single.