Start with the idea
Start with a three-note pivot. In this example, the pivot is 1/2/7 and both wings also include 7. No matter what the pivot uses, one pattern cell must be 7, so a cell that sees the whole pattern cannot keep 7.
Look for this pattern
Look for a few connected squares that share candidates. One shared number may be removable from squares that see the whole pattern.
This empty board keeps the puzzle numbers out of the way so the pattern is easier to see.
Example
5
3
6
1
2
7
5
9
8
6
8
3
7
9
6
4
1
7
8
1
2
7
6
6
2
8
4
9
5
8
7
Look here firstStart with the 1/2/7 pivot. All three pattern cells share the number 7.
This technique reviews candidates instead of solving a square right away.
The red cell sees the whole pattern, so it cannot keep the shared 7.
- Find a three-note pivot.
- Find two wings that share two of the pivot's notes.
- Remove the shared note from cells that see the pivot and both wings.
pivot cellcells in the patternnotes to remove
When to look for it
Use it when a pivot has three notes and two nearby wings each share two of those notes.
How to use it
- Find a pivot with exactly three notes.
- Find two wings that each share two of the pivot's notes.
- Remove the shared note from any cell that touches the pivot and both wings.
Common mistakes
- Unlike XY-Wing, the removal cell must also touch the pivot.
- The removable note is the one shared by all three pattern cells.