The Halloween Gambit

1. e4 e5
2. Nf3 Nc6
3. Nc3 Nf6
4. Nxe5

Also known as the Müller-Schulze gambit, or the Leipzig gambit is an aggressive variant of the Four Knights Game, where an early knight is traded by white for a pawn. It's a large sacrifice, but the white player gains tempo and development.

Whilst this seems poor, if the black player accepts the gambit he exposes a black knight that is chased by white, who aims for a quick victory.

The computer program Brause, has numerous wins playing this opening in the Blitz format due to the threats it can present, often in less than 15 moves. WGM Eva Repkova scores 2 out of 3 with the Halloween Attack as a blitz gambit proving it can be a very dangerous weapon with enormous tactical potential.

The consensus is that if black can stabilise they can use the lead to take victory, often quoting Pinski's reply.

4...Nxe5
5.d4 Nc6
6.d5 Bb4!
7.dxc6 Nxe4
8.Qd4 Qe7