X-Wing
Fish & Wings13 / 32Two rows, two columns, four corners — a rectangle traps the digit.
Find two rows in which a digit has exactly two possible cells each — and those cells line up in the same two columns. The four cells form a rectangle, and the digit must occupy two opposite corners of it.
Whichever diagonal it takes, both columns receive their digit inside the rectangle. Everything else in those two columns is free of it. The same works with rows and columns swapped.
See it in action
Step 1 of 4
The setup
Pick a digit and scan the rows that hold it in exactly two cells. Note the column pair of each such row — a repeat means an X-Wing. Step through this real position to see it happen.
Practice
Find the X-Wing and remove its digit from the rest of the two covered lines.
Drill 1 of 29Tap a cell, then the candidate digit you want to remove.