Practice
Champion technique

Swordfish

An X-wing on three lines. When a digit fits only two or three cells in each of three rows, all in the same three columns, those rows use up the digit in those columns. Rule it out of the rest of the three columns. The same works with rows and columns swapped.

1FocusOnly what mattersNext
2Notes givenFull grid, notes filled inLocked
3Your own notesFull grid, you make the notesLocked
4Against the clockHow many in a row?Locked
Start

5 right in a row passes a level