Swordfish Sudoku Technique
An advanced Swordfish page showing how bigger candidate patterns fit into a full learning cluster.
Swordfish extends the same candidate-elimination discipline as X-Wing into a larger three-line pattern. This page keeps the idea focused: one advanced technique, one clear explanation, and one easy route back into play.
What is Swordfish?
Swordfish is a candidate pattern involving three rows and three columns for the same digit.
Like X-Wing, it works because the candidate structure forces a constrained set of placements.
When to use it
Use it on expert-style boards when simpler eliminations have failed.
It belongs in the content cluster even if only a subset of players ever need it.
Step-by-step example
Step 1
Choose one digit
Search the grid for a digit whose candidates align across three rows or three columns.
Step 2
Confirm the three-line structure
The pattern only works when the same three columns or rows are involved.
Step 3
Clear the matching candidates outside the pattern
Those extra candidates cannot survive once the Swordfish structure is real.
Practice Swordfish on a live board
This live board lets you practice the technique immediately while the idea is still fresh.
36% complete
29/81 correct · 29 filled
Interactive practice board
Use Explain Move to study the next logical step without auto-filling the answer.
Instant validation
Mark wrong placements as you enter them.
Reveal mistakes
Toggle visible mistake highlights when you want a cleanup pass.
Hints
0
Win rate
0%
Streak
0
Pick a cell to start.
Related techniques and next steps
Technique pages work best as a cluster. Once one concept clicks, the player should always have a relevant next page to open.