Swordfish
swordfish
LevelNot seen in a hint yet
How it works
If a digit in three rows or columns is confined to the same three crossing lines, those three lines must take all of its placements.
The digit can therefore be removed from other cells on those lines. It is an X-Wing widened to three lines; the fish shape gives Swordfish its name.
Worked example
1
5
2
7
4
6
4
5
7
7
6
5
9
2
4
6
3
8
1
7
3
6
9
4
5
2
6
3
8
4
9
9
5
6
9
6
3
● evidence✕ eliminated★ confirmed
In row 1, row 5, row 8, 2 can only appear in column 1, column 4, column 5 (marked ●).
Those three base lines occupy column 1, column 4, column 5, so 2 is removed from the other 7 cells of those covers (✕).
Examples I encountered
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