Sudoku solving technique · Intermediate
Hidden Pair
Two digits that appear in only the same two cells of a unit.
What is a Hidden Pair?
When two numbers only appear as candidates in the same two cells within a unit, those cells must contain those two numbers. You can remove all other candidates from those two cells.
How to spot a Hidden Pair
In one unit, count for each digit how many cells still have it as a candidate. If two digits each appear in only the same two cells, you have a Hidden Pair. Those cells usually carry other candidates that hide the pattern; those are the ones you remove, and the Hidden Pair becomes a Naked Pair.
- Difficulty
- In Sudoku Pro, this technique belongs to the Intermediate level.
- Learning path
- Technique 4 of 20 on the learning path
An example from the app
| Pattern (purple). Candidates 1, 2. Eliminated 3 | Pattern (purple). Candidates 1, 2. Eliminated 4 | Candidates 3, 4 | Candidates 3, 4 |
| Empty | Empty | Given 1 | Given 2 |
| Empty | Empty | Empty | Empty |
| Given 4 | Given 3 | Given 2 | Given 1 |
Small digits are candidates. Crossed-out digits can be removed in this step.
- Pattern (purple)