2-String Kite: A Row and a Column, Strung Together

If you've just read Skyscraper, the 2-String Kite will feel immediately familiar — it's the same "either/or" reasoning, just with a row and a column instead of two rows.

What is a 2-String Kite?

A 2-String Kite pairs a row where a digit fits in exactly two cells with a column where it fits in exactly two cells. One cell from the row and one cell from the column sit in the same box — so they can't both hold the digit.

If the row's box-cell is the digit, the column's box-cell isn't, forcing the digit into the column's far end. If it isn't, the row's far end must be it. Either way, one of the two far ends holds the digit — so any cell that sees both can't.

Why it works

It's the same logic as the Skyscraper, just with the two "strings" running in different directions. The two cells sharing a box can't both be the digit, which forces exactly one of the two far-end cells to hold it — you just don't know which.

A worked example

Here's the exact board the app uses for its own 2-String Kite lesson:

Singles, Naked/Hidden Pairs, and Pointing Pairs clear the easy cells:

That's where it stalls. Row 8 has a 7 in only two cells, column 3 has a 7 in only two cells, and one cell from each — R8C2 and R7C3 — sit in the same box:

Blue & violet: the cells the logic runs on · Rose: where the elimination lands

R8C2 and R7C3 can't both be the 7, which means one of the far ends — R8C4 or R2C3 — must be. The cell where the row's far column (C4) meets the column's far row (R2) — that's R2C4 — sees both far ends and loses its 7, and the rest of the grid opens up from there.

How to spot one

1. Find a row and a column where a digit fits in only two cells each.
2. Check whether one cell from the row and one from the column fall in the same box.
3. If so, the cell where the row's other column meets the column's other row is the usual target — eliminate the digit there.