Hidden Pair

Easy

Two digits are confined to the same two cells in a unit; all other candidates in those cells are eliminated.

How It Works

When two digits can only appear in the same two cells within a unit, those two cells must contain those two digits. Therefore all other candidates in those two cells can be eliminated.

Example: If 4 and 7 are only candidates in R2C3 and R2C5 within row 2 → Remove all other candidates from those cells.

Example

1	9	4	68	258	3	26	7	58
2	37	5	1678	789	79	136	4	89
6	37	8	17	4	2579	123	13	59
3	2	1	4	57	57	8	9	6
8	4	6	9	3	1	5	2	7
9	5	7	2	6	8	13	13	4
4	6	3	5	29	29	7	8	1
5	1	2	78	78	4	9	6	3
7	8	9	3	1	6	4	5	2

Key cells of the techniqueCells where elimination is appliedCandidate to be placedEliminated candidate (crossed out)

Practice with a Real Puzzle

This 9×9 puzzle is solver-verified to require this technique on its solution path.

Easy32 givensStrict