Start with the idea
Start with one number and two lines that each have two possible spots. In this example, the number is 4. At least one far end of the pattern must be 4, so a cell that sees both far ends cannot also be 4.
Look for this pattern
Look for linked two-choice spots for one number. The links create a pattern you can follow around the board.
This empty board keeps the puzzle numbers out of the way so the pattern is easier to see.
Example
5
3
7
6
4
1
5
4
9
8
6
8
2
4
9
3
8
3
1
7
4
4
6
6
2
8
4
1
9
5
8
7
Look here firstFocus on the number 4. Two rows each have exactly two possible 4s, and their far ends point at the same cell.
This technique reviews candidates instead of solving a square right away.
At least one far end must be 4, so the cell that can see both far ends cannot keep 4.
- Choose one number.
- Find two rows or columns with two possible spots for it.
- Remove that number from a cell that can see both far ends.
first colorsecond colornotes to remove
When to look for it
Use it when one note forms two two-position lines that do not make a rectangle.
How to use it
- Pick one digit and find two rows or columns where that digit has exactly two possible spots.
- Identify the two end cells that do not line up with each other.
- Remove the digit from any cell that touches both end cells.
Common mistakes
- Skyscrapers use one digit only.
- Only remove the note from a cell that touches both end cells.