Hidden pairs: find two digits with two homes
A hidden pair is found by counting digit locations across a unit, not by looking for two already-clean cells.
Key idea
If two digits occur only in the same two cells of a unit, those cells must contain the two digits and all their extra notes are impossible.
See the move, step by step
Scan row 3 for the only homes of 5 and 9.
Step 1 of 4
Count locations across the row
Ignore candidate-list length and track where each missing digit can still appear in row 3.
Step 2 of 4
Find the two shared homes
Digits 5 and 9 appear only at R3C3 and R3C4, even though both cells contain other notes.
Step 3 of 4
Strip the hiding candidates
Remove 3 and 7 from R3C3, and 3, 6, and 7 from R3C4.
Step 4 of 4
Expose the pair
Both cells now contain only 5 and 9. Their order is unknown, but the pair is no longer hidden.
Try it on today's puzzle
Within each unit, look for two digits with identical two-cell location sets. Do not require the cells to start as bivalue cells.
Play today