Finned Swordfish

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

235
346
1
2367
2367
8
45
9
25
235
46
236
1236
12369
1269
458
7
1258
789
12
45
12
36
13
2
36
85
16
947
19
169
5
1267
1267
4
12
83
4789
12
36
125
125
1238
5
23
4
1368
126
7
126
9
6
139
7
123
12389
129
358
125
4
12389
139
45
123689
7
38
126
128
Key cells of the techniqueCells where elimination is appliedCandidate to be placedEliminated candidate (crossed out)

Practice with a Real Puzzle

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

Hard24 givensStrict