Medium Used from medium puzzles up.
Locked Candidates: Claiming
A line's candidates in one box
The same idea the other way round: in a row or a column, the candidates for a digit sometimes all lie inside one box.
The digit is then in that part of the line, so it cannot be anywhere else in the box: remove it from the box's other cells.
What to look for
Find a row or a column where the candidates for one digit all fall inside one box.
Example
- The cells the technique relies on
- Cells where it removes candidates, struck out in red
Practise it
In the app, Learn › Locked Candidates: Claiming sets exercises on real positions, then a full puzzle that needs this technique and nothing harder.