Hidden Pair
Working with Candidates6 / 32Two digits that only fit in the same two cells.
Flip the perspective of the naked pair: instead of looking at cells, look at digits. If two digits are each restricted to the same two cells of a unit, those cells belong to them — whatever else the pencil marks claim.
The pair hides behind extra candidates in its own cells. Clearing those extras is the move, and it can turn messy cells into clean bivalue building blocks for later techniques.
See it in action
Step 1 of 4
The setup
For each unit, note the digits that only appear in two cells. When two such digits share both cells, you've cornered a hidden pair. Step through this real position to see it happen.
Practice
Find the hidden pair and strip all other candidates from its two cells.
Drill 1 of 29Tap a cell, then the candidate digit you want to remove.