Lesson
White to move. Main line: 1. Qxf8+ Kxf8 2. Rxa8+
Qxf8+ looks like a bad exchange until the alignment on the eighth rank is noticed. The check forces Kxf8, moving the king onto the same rank as its queen and removing the rook that stood between White’s rook and a8.
Rxa8+ then captures Black’s queen and checks the king across the rank. Materially, White traded a queen for a rook and queen, emerging a rook ahead while retaining the initiative through the final check.
A deflection can target a king as well as a defending piece. When two valuable pieces share a rank or file, look for a forcing capture that changes which one stands in front of the other.