Hyper pair
A naked pair where both cells lie in the same hyper region of a Hyper Sudoku (Windoku). Eliminates the two pair digits from every other cell of that region.
A hyper pair is the Hyper Sudoku analogue of a classic naked pair: two cells lying in the same hyper region whose candidate set is reduced to the same two specific digits. Because every hyper region obeys the uniqueness rule, those two digits must occupy those two cells in some order — and they can be eliminated as candidates from every other cell in that hyper region.
How it works
Consider the top-left hyper region (rows 2–4, columns 2–4) in a medium Hyper Sudoku. Two cells inside it — say (2, 3) and (3, 4) — both have candidate set {6, 8}. The uniqueness rule on the hyper region forces 6 and 8 to occupy those two cells between them. None of the other seven cells in the hyper region can hold a 6 or an 8.
The deduction is identical in shape to a box-based naked pair; the unit being scanned is just the hyper region rather than a standard 3×3 box. Because a hyper region overlaps four standard boxes, the eliminations from a hyper pair can ripple across more of the board than a standard box-based naked pair would.
When it fires
Hyper pairs appear at the medium tier and above. At easy, the hyper regions usually don't tighten enough to produce them. At hard and expert, hyper pairs are a regular fixture — and because the hyper region overlaps four standard boxes, the downstream eliminations a hyper pair triggers tend to be productive in unexpected places.
The same mechanic generalises to hyper triples (three cells, three shared digits) by exact analogy with the classic naked triple.
For the wider list of hyper-region-aware moves and the practical scan habit, see when hyper regions narrow it down.
See also
- Hyper Sudoku— A Sudoku variant with four extra 3×3 regions overlaid on the standard grid, each obeying the uniqueness rule. Also called Windoku in continental European communities.
- Hyper region— One of the four extra 3×3 regions in a Hyper Sudoku (Windoku). Each region carries the same digit-uniqueness rule as a row, column, or standard 3×3 box.
- Hyper-only cell— A Hyper Sudoku (Windoku) deduction: a cell where row, column, and standard box together leave multiple candidates, and the hyper region alone forces the digit.
- Cross-region deduction— A Hyper Sudoku move using the overlap between a hyper region and a standard 3×3 box: locking a digit to a shared sub-region eliminates it from the rest of both units.
- Naked pair— Two cells in the same unit whose candidate sets are identical and contain exactly two digits. Together they claim those digits across that unit and rule them out elsewhere.
- Hidden pair— Two digits whose only possible cells inside a unit are the same two cells — even if those cells still show other candidates. The digit-first sibling of the naked pair.
Read more
- When hyper regions narrow it down
A practical tactic for Hyper Sudoku and Windoku: scan the hyper region as a fourth unit when row, column, and box reasoning runs out. Worked patterns and where they fire.
- The four hyper regions
Where the four extra 3×3 regions sit inside a Hyper Sudoku (Windoku) board, why they're positioned that way, and how to spot them while solving.