Finned X-Wing

Hard

X-Wing with extra "fin" cells in one row; eliminations are restricted to cells seeing the fin's box corner.

How It Works

Almost an X-Wing, but one row has extra candidate cells ("fins"). Eliminations still occur, but only for cells that see both the normal X-Wing corner AND all fin cells (i.e., in the same box as the fin).

The fins restrict the elimination scope but the technique still works.

Example

1
249
249
49
57863
37
3479
568
349
12
79
6
379
81
239
239
45
79
23
1234
124
76
34
985
357
357
47
349
349
8216
986215374
46
27
38
237
159
28
25
1259
3
89
29
674
128
8
1279
1279
5
2479
249
63
12
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