Skyscraper
skyscraper
LevelNot seen in a hint yet
How it works
When a digit has exactly two cells in each of two rows or columns, each pair is a strong link. If one end of each link meets on one line, one of the two far ends must hold the digit.
Any cell that sees both far ends can lose the digit. The two links resemble tall pillars, hence the name Skyscraper.
Worked example
5
8
7
8
7
3
1
5
4
7
5
8
1
2
7
4
9
3
3
7
5
2
6
1
9
3
1
7
8
5
4
1
6
1
9
5
4
3
5
3
7
1
9
● evidence✕ eliminated★ confirmed
The 6 strong links in row 5, row 8 meet at R5C1, R8C1 (marked ●).
One of the remaining ends R5C9, R8C7 holds 6, so it is removed from 1 cells that see both ends (✕).
Examples I encountered
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