Two-string kite

Two-string kite is structurally similar to skyscraper, but the strong links are a row and a column instead of two rows. One cell from each line shares a box (the 'anchor'). The other two cells are the 'ends.' One of the ends must be the digit, so cells seeing both ends can be eliminated.

Kites and skyscrapers cover most of what people call 'turbot fish' patterns in older sudoku literature.

When to look for it

After exhausting simpler digit-by-digit logic, look for digits with exactly two candidate cells in some row and exactly two in some column — sharing a box.

How to apply it

1. Pick a digit.
2. Find a row with exactly two candidates and a column with exactly two candidates.
3. Check that one cell from each line shares a box (anchor).
4. Eliminate the digit from cells that see both other ends.

Example