The Naked Triple Technique in Sudoku

Naked Triple

A Naked Triple occurs when three cells within the same house, that is, a row, a column, or a block, contain only three candidates in total. In other

words, those three numbers do not have to be present in all three cells but the number in total across these cells has to be three to qualify them.

Upon determination, those three digits have to be eliminated from the possibility grids of other cells located within that particular house.

Example1:

As an illustration, in the first example, the cells R2C2, R4C2, and R5C2 are all part of Column 2. Collectively, they only have the candidates 3, 6,

and 9. So, we can understand that those three cells must contain those three numbers in some order, however we do not know which number goes to

which cell yet. What we do know is that 3, 6, and 9 will not be found in any other cell within Column 2. So for example, R1C2 may remove 6 as a

possibility. The logic completes the rest of the puzzle with ease using only singles.

Example2:

In the second example, we have a Naked Triple subset in Block 2. The three cells R3C4, R3C5, and R1C5 together contain only one candidate 1, 2, and

6. Since the block needs to accomodate them in the mentioned three cells, they have to get eliminated from all the remaining cells in that block.

Once you master triples like this one, check out Naked Pairand Hidden Triple to see how the same logic extends across different group sizes.