Hammerschlag

The Hammerschlag, also known as the Fried Fox or Pork Chop Opening, answers 1. f3 e5 with 2. Kf2, one of several move sequences grouped under the Bongcloud name. The king steps onto the square vacated by the f-pawn, giving up castling and placing itself on the g1–a7 diagonal, where a bishop on c5 can check it. The stated rationale is to trade pieces quietly, limit attacking chances against the exposed king, and later use that king as an active central piece in the endgame. The pawn on f3 and an early c3 are meant to support a delayed d4. Engines rate Black clearly better, yet online results are almost exactly level.

Black's most common reply is 2...d5, taking a broad share of the center. Next come 2...Nc6 and 2...Bc5+, the latter developing with check along the king's diagonal, although White scores relatively well against it. After 2...d5, 3. c3 prepares d4 and opens the d1–a4 diagonal for the queen. Simon Williams won with the line against Martin Simons at the 1999 British Championship after 2...d5 3. e3 Nf6 4. d4 Nc6 5. Bb5, and Magnus Carlsen beat Wesley So with it in a 2020 Banter Series blitz game, a defeat So described as humiliating.