Finned Swordfish

Very Hard

Swordfish with extra fin cells; eliminations are restricted to cells in the fin's box.

How It Works

Finned X-Wing extended to three rows. Swordfish conditions are almost met but extra "fin" cells exist in one of the rows. Eliminations are restricted to cells in the same box as the fin that also see the Swordfish column.

Example

8
3
5
3
16
4
3
16
9
2
19
46
79
91
57
8
6
79
91
58
82
45
37
1
26
28
4
26
35
8
49
36
4
3
46
3
19
16
3
49
24
7
14
12
3
49
26
4
26
18
3
59
79
52
39
37
68
68
5
3
49
3
56
3
3
4
3
9
47
16
58
78
59
24
27
3
Key cells of the techniqueCells where elimination is appliedCandidate to be placedEliminated candidate (crossed out)

Normal Swordfish pattern plus fin cells in one row. Eliminations only apply within the box containing the fin, for cells seeing the relevant Swordfish column.

Practice with a Real Puzzle

This 9×9 puzzle is solver-verified to require this technique on its solution path.

Hard24 givensStrict