Chess Openings Explained: Halloween Gambit

The Halloween Gambit, also known as the Müller-Schulze Gambit, is an aggressive chess opening gambit in which White sacrifices a knight early on for a single pawn. The opening is an offshoot of the normally placid Four Knights Game and is defined by the moves:

The theoretician Oskar Cordel reported in 1888 that Leipzig club players used the opening to dangerous effect, but he did not believe it was sound. Their name for it, Gambit Müller und Schulze, was not after any players by those names, but rather a jocular German equivalent of  "Smith and Jones" or, "Tom, Dick, and Harry". The modern name "Halloween Gambit" was given by the German player Steffen Jakob, who explained that "Many players are shocked, the way they would be frightened by a Halloween mask, when they were mentally prepared for a boring Four Knight's Game, and then they are faced with Nxe5."

White's objective is to seize the center with pawns and drive back Black's knights. After 4... Nxe5, White usually plays 5. d4, after which Black can retreat his knight to either g6 or c6.

5... Ng6 retreat

When Black retreats 5... Ng6, White chases the f6-knight with 6.e5. Then, after 6...Ng8 7.Bc4, former world champion Max Euwe recommends 7...d5 8. Bxd5 c6, contending in volume 11 of his opening series that Black has a decisive advantage. 

Instead of holding on to the extra piece with the usual 6...Ng8, a more logical conclusion according to Eric Schiller is 6...Bb4, giving Black the better game after 7. exf6 Qxf6 with a lead in development and pressure in the center.

When Black retreats 5...Nc6, White chases the knight again with 6. d5. Then Black has 6... Ne5 (the Main Line), or 6...Bb4 (Pinski's move).

6...Ne5

After 6...Ne5, White chases again with 7.f4. Then after 7...Ng6, the game usually continues with 8. e5 Ng8 9. d6 cxd6 10. exd6 (see diagram).