Mirrored from Sudopedia, the Free Sudoku Reference Guide
A Skyscraper is a single-digit solving technique which uses a particular pattern of Turbot Fish.
It has been introduced as a separate technique, because the Turbot Fish technique does not use a single pattern and is not easy to learn by the average Sudoku player.
Here is an example:
The candidates for digit 4 in rows 4 and 7 are conjugate pairs. Since the 2 candidates in column 7 cannot be true together, at least one of r4c2 or r7c1 must be true. They could also both be true. We call this a connected pair. The two red candidates can be eliminated, because they can both see r4c2 and r7c1.
A Skyscraper is also a Sashimi X-Wing. Also, Skyscraper can be replicated using Multi-Colors.
The following is a practice puzzle for 2-String Kite and Skyscraper. The other techniques that are required are SSTS minus the coloring techniques. It is generated by Simple Sudoku.