Sudoku techniques · Master
Two-String Kite in Sudoku
A Two-String Kite takes two strong links on one number, one running along a row, one along a column, whose near ends sit in the same box. The box can only supply the number once, so at least one far end must hold it, and any cell that sees both far ends loses the candidate.
Why it works
When two strong links on one number, one in a row and one in a column, have near ends that share a box, at least one far end must hold it, and any cell seeing both far ends loses that candidate.
How to spot it
Two strings, one knot. The knot is the shared box.
- Find a row where the number has exactly two spots, and a column where it also has exactly two.
- Check whether one end of each lands in the same box. That is the knot.
- The elimination is the single cell where the two far ends' lines cross.
Builds on
Worked example
These are the app's own lesson boards. Step through them the same way a hint does.
- 1
For 6, a row and a column each have that candidate in only two cells (a strong link). One cell from the row and one from the column (the near ends) share a box, and the other two are the far ends, forming a Two-String Kite!
- 2
6 must be in at least one of the two far ends, so we can remove the candidate 6 from any other cell that sees both far ends.