French Defense Diemer Duhm Gambit Puzzle (Rated 1397): Win Material — Discovered Check

This middlegame puzzle is a classic example of tactical coordination turning a material deficit into a winning attack. White’s active knight and queen create a forcing sequence that begins with a discovered check, pulling the black king into a vulnerable square and exposing loose pieces behind it. The key idea is that checks can do more than chase the king: they can also win time, overload defenders, and set up a clean material gain on the next move.