Technique

Swordfish

X-Wing's three-line version: a digit confined, across three rows, to the same three columns overall. It can be cleared from the rest of those three columns.

💡 What It Is

A fish pattern spanning three lines instead of two - each of the three rows offers the digit in some subset of the same three columns.

🔍 How To Spot It

Pick a digit. Find three rows where every candidate for it falls within the same three columns overall (each row doesn't need all three, just a subset).

✅ Why It Works

Across those three rows, the digit has to use up exactly those three columns between them - so no other cell in those columns can hold it.

📝 Worked Example

Digit 6's candidates in rows 1, 4, and 7 fall only within columns 2, 5, and 9 (not every row uses all three columns). Eliminate 6 from every other cell in columns 2, 5, and 9.

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