Medium Used from medium puzzles up.
Naked Pair
Two cells, the same two candidates
Two cells of a unit with exactly the same two candidates, say 3 and 7, will hold those two digits, one each. Which way round is not known yet.
Either way, 3 and 7 are used up in that unit: remove them from its other cells.
What to look for
Find two cells of one unit with the same two candidates and nothing else.
Example
- The cells the technique relies on
- Cells where it removes candidates, struck out in red
Practise it
In the app, Learn › Naked Pair sets exercises on real positions, then a full puzzle that needs this technique and nothing harder.