Sudoku techniques · Master
Grouped Two-String Kite in Sudoku
A Grouped Two-String Kite is a Two-String Kite in which one or both strings reach the shared box through a group of cells rather than a single cell. A number confined to two or three cells of one box that share a line behaves exactly like one cell, which is what lets the same logic run.
Why it works
When a row and a column each have a number as a candidate only in one far cell outside a shared box and a group inside it, and the two groups share no cells, the box can satisfy at most one group, so at least one far end must hold that number, and any cell seeing both far ends loses that candidate.
How to spot it
Once you accept that a group of cells can stand in for one cell, a lot of near-misses turn into real patterns.
- A group is two or three cells of one box that also share a row or column.
- The two groups inside the shared box must not overlap: if they share a cell, the box could satisfy both and the logic collapses.
- Everything else is a plain kite: the far ends still do the work.
Builds on
Worked example
These are the app's own lesson boards. Step through them the same way a hint does.
- 1
For 2, the outlined row and column each hold that candidate in only one far cell plus one or more cells inside the shared box. Each line is a strong link between its far end and its box group, and the box can hold 2 only once, so the two groups cannot both take it. This is a Grouped Two-String Kite!
- 2
If either far end were not 2, its line would push 2 into its box group, and the box would then force the other line onto its far end. At least one far end must be 2, so we can remove the candidate 2 from the red cell that sees both far ends.