Hard

Swordfish

What it is

Like X-Wing, but with three rows and three columns.

How to spot it

Find three rows where a digit has two or three possible cells, all within the same three columns. Then those rows supply the digit for all three columns.

Example

Basis
Removed / placed

In rows 1, 5 and 8, 7 only fits in columns 2, 5 and 8. The three 7s of those rows fill the three columns, so 7 is removed from the rest of those columns – here r3c2, r6c5 and r9c8.

Used from level: Hard