SUDOKU
IntermediateUsefulness: Medium

Hidden Pair

Two digits that can only appear in the same two cells of a house, disguised by extra candidates. Those extras can be stripped away.

1 and 8 can only live in these two cells, so their other candidates are removed.

patterneliminatesolved

How to spot it

  1. 1Find two digits whose only homes in a house are the same two cells.
  2. 2Those cells must take those two digits between them.
  3. 3Delete all other candidates from that pair of cells.

When to use

When a house looks candidate-heavy but two digits are quietly restricted.

Common mistake

Overlooking them entirely — hidden pairs wear a disguise of surplus candidates.