Hidden Triple
When three numbers can only fit in the same three cells.
Explanation
In one row, column, or box, if three digits can appear only inside the same three cells, those cells must contain the triple. Other candidates in those cells can be removed.
Practice tip
Track where each digit can still go in one unit, then look for three digits sharing the same three cells.
Example steps
- Choose one unit and mark the possible cells for each digit.
- Find three digits whose possible cells collapse to three positions.
- Keep the triple digits there and remove all other notes in those cells.