Techniques · Expert

XYZ-Wing

A pivot with three candidates A/B/C sees two pincers, A/C and B/C. Whatever the pivot is, one of the three cells is C. So C can be removed from any cell that sees the pivot and both pincers.

How to spot it

Start from a cell with three notes and look for two two-note cells it can see, each using two of its digits and sharing one. Only cells that see all three lose the digit, which usually means cells in the pivot's box.

Example

Pivot r1c2 (2/4/9) with pincers r1c3 (2/9) and r9c2 (4/9): one of them must be 9, so 9 can be removed from cells that see all three (XYZ-Wing).

the pattern cells that lose a candidate (crossed out)