Ruy Lopez:Schliemann Defense

Also called the Jaenisch Gambit. Black strikes back at once with 3...f5, a sharp counterattack in the spirit of the King’s Gambit.

It is reached after 6 moves: 1. e4 e5 2. Nf3 Nc6 3. Bb5 f5. It is a line of the Ruy Lopez.

White is to move and has 33 legal moves. Over the next four moves — two for each side — the game can branch into 1,028,427 different games. Those games reach 337,015 different positions: most positions can be reached in more than one way, 3.1 on average.

The Lichess opening list names 8 further lines after this position, such as Dyckhoff Variation (4. Nc3) and Exchange Variation (4. Bxc6).

The same moves can be played in 18 different legal orders that all reach this position. For example 1. Nf3 e5 2. e4 Nc6 3. Bb5 f5, which starts as the Zukertort Opening.