Three Knights Opening

It is reached after 5 moves: 1. e4 e5 2. Nf3 Nc6 3. Nc3.

Black is to move and has 31 legal moves. Over the next four moves — two for each side — the game can branch into 842,247 different games. Those games reach 285,582 different positions: most positions can be reached in more than one way, 2.9 on average.

The Lichess opening list names 51 further lines after this position, such as Four Knights Game (3... Nf6) and Steinitz Defense (3... g6).

The same moves can be played in 12 different legal orders that all reach this position. For example 1. Nf3 e5 2. e4 Nc6 3. Nc3, which starts as the Zukertort Opening.