Start with the idea
Start with one number. In this example, three rows need 8, and all of their possible 8s fit inside the same three columns. Those columns are reserved for the pattern's 8s, so other 8s in those columns cannot be correct.
Look for this pattern
Look for one number that lines up across matching rows and columns.
This empty board keeps the puzzle numbers out of the way so the pattern is easier to see.
Example
5
8
7
8
8
6
1
9
5
3
8
6
6
3
4
8
8
1
7
2
6
6
2
1
8
9
4
1
9
5
8
8
Look here firstFocus on the number 8. Three rows keep their possible 8s inside the same three columns.
This technique reviews candidates instead of solving a square right away.
Those columns are reserved for the pattern's 8s, so other 8 notes in those columns cannot be correct.
- Choose one number.
- Find three rows whose possible spots fit the same three columns.
- Remove that number from the other cells in those columns.
8s in the Swordfish8 notes to remove
When to look for it
Use it when an X-Wing almost appears but a third row or column completes the pattern.
How to use it
- Pick one digit and scan rows or columns.
- Find three rows or columns whose notes fall in the same three crossing lines.
- Remove the digit from other cells in those crossing lines.
Common mistakes
- Each pattern row or column usually has two or three notes for the digit.
- Do not mix different digits in one fish.