Little Sudoku

Techniques › Naked Quad › Practice

Practise the Naked Quad

Four cells sharing four candidates between them. Rare, and usually preempted.

8 real positions, each taken from an actual puzzle at the moment this was the cheapest move available. Two steps: find the cells that form the pattern, then find the candidate it rules out. A near miss tells you how many you had right, so getting it wrong is worth something.

Select the cells that form the pattern, then check. 1 / 8
9 6 1 8 7 2 4 3 5
35 35 8 4 6 1 9 7 2
7 2 4 5 3 9 1 6 8
6 9 5 7 1 8 2 4 3
1 4 7 3 2 6 8 5 9
38 38 2 9 4 5 7 1 6
458 158 6 12 9 34 35 28 7
2 7 39 16 58 34 356 89 14
458 158 39 126 58 7 356 289 14

How to spot it

Four cells with two to four candidates each whose union is four digits. Only worth hunting when a house has seven or more empty cells and nothing simpler applies.

Full explanation on the Naked Quad reference page.

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