Naked Triple
A Naked Triple extends the Naked Pair to three cells: three cells in one unit whose candidates, pooled together, amount to only three digits. Those three cells must take those three digits in some order, so the digits can be removed from every other cell in the unit.
The subtlety is that no single cell needs to show all three candidates. Suppose a column contains cells marked 2/6, 2/9 and 6/9. The union is {2, 6, 9} — three digits across three cells — and that is enough. Try giving any other cell in the column a 2: the first cell becomes 6, the third becomes 9, and the second cell is left with nothing. Every assignment outside the triple breaks it, so 2, 6 and 9 come off the rest of the column. Triples of the shape 2/6/9, 2/6, 6/9 or even three identical 2/6/9 cells all work the same way.
To spot one, gather the cells in a unit that hold two or three candidates and test whether any three of them pool to exactly three digits. This is genuinely harder to see than a pair, which is why it ranks above pairs in difficulty — the broken form, where each cell shows only two of the three digits, hides well in a marked-up grid.
Look for Naked Triples in units with few empty cells; with only four or five cells open, three of them pooling to three digits is common. And remember the complement: a naked triple among five open cells means the other two cells form a hidden pair of the remaining digits.
- Cells with two candidates count — a triple does not require any cell to show all three digits.
- Focus on units with four to six empty cells, where triples are most likely and easiest to verify.
- Pool the candidates and count: three cells, union of exactly three digits, then eliminate those digits elsewhere in the unit.