Swordfish
Rated 4.6 on the technique scale · A three-line fish.
Swordfish generalises the X-Wing to three rows: if a digit is confined to three columns across three rows, it can be removed from the rest of those three columns.
It is worth 4.6 points and shows up in hard and expert puzzles, often right after an X-Wing has been exhausted.
When you are stuck after X-Wings, count how many times each digit can appear in each row before reaching for chains.
Practice it: swordfish shows up most often in hard and expert puzzles. Browse those levels →
How the rating uses it
When a puzzle cannot be finished with easier techniques, the solver applies Swordfish and adds 4.6 to the puzzle's score. The hardest technique a puzzle needs decides its level, and puzzles with 26 clues or fewer move up one level.