Sue de Coq

A box/line intersection splits its digits between the line and box.

Learn the Sue de Coq technique: two cells where a box meets a line hold four digits split between a line cell and a box cell, so each pair leaves its house.

How to use it

1. Find the intersection pair. Find two cells where a box and a line (row or column) overlap that together hold exactly four candidates.
2. Split with two bivalue cells. Find a two-candidate cell in the line (outside the box) holding two of the four digits, and a two-candidate cell in the box (outside the line) holding the other two.
3. Clear each pair from its house. The four cells use the four digits between them, so the line pair leaves the rest of the line and the box pair leaves the rest of the box.