A hidden triple occurs when three digits can only appear in the same three cells within a house.
Understanding the Concept
Three candidates are restricted to the same three cells in a house.
These cells likely contain other candidates, hiding the triple.
Not all three digits need to appear in all three cells.
Once identified, remove all other candidates from these three cells.
Hidden triples are among the hardest patterns for humans to spot.
They're more common than naked triples in harder puzzles.
Examples
Hidden Triple {1, 4, 6} in Row
In this row, digits 1, 4, and 6 can only appear in three specific cells. These cells have other candidates too, but since 1, 4, 6 are confined to just these cells, we eliminate all other candidates from them.
8
3
9
2
2
8
3
9
2
8
9
3
7
123456789
123456789
123456789
3
7
3
7
1
9
2
3
9
6
2
9
2
3
Pattern / InvolvedEliminated
Pro Tips
- •Track where each digit can go in each house
- •Look for three digits limited to the same three cells
- •Hidden triples often involve many candidates to sift through
- •Use systematic digit-by-digit checking to find them
