Franken Swordfish

Level 11 · Red Belt

Strategy:

Franken Fish

Overview

Franken Swordfish is a 3-house Franken fish that mixes boxes with rows and columns. The base and cover sets each use three houses, with at least one box included.

How It Works

  1. Find a digit confined within 3 base houses (rows, columns, or boxes).
  2. Cover with 3 houses from other types, including at least one box.
  3. Eliminate the digit from cover set cells not in the base set.

Example

Starting position

Look for Franken Swordfish.

1

Found a Franken Swordfish on digit 2

Found a Franken Swordfish on digit 2. The base set is: Row 8, Box 1, Box 3.

2

2 is confined to the cover set

The cover set is: Column 2, Column 3, Column 7. Digit 2 in the base set is confined to these 3 cover houses.

3

Cover-only 2 candidates can be removed

Any 2 in a cover house but outside the base set can be eliminated.

4

Cover candidates outside the base set

These cover-set candidates are outside the base set and must be removed: .

5

Remove 2 from

Eliminate 2 from .

6

Result

Result after applying the technique.

Tips & Patterns

  • Franken Swordfish are quite rare.
  • The mixing of boxes with lines makes the pattern harder to visualize than standard Swordfish.
  • Look for digits confined to specific box-line intersections.