Italian Game:Two Knights Defense

Black counterattacks e4 with 3...Nf6 instead of copying White’s moves. After 4. Ng5 the game becomes sharp at once.

It is reached after 6 moves: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6. It is a line of the Italian Game.

White is to move and has 33 legal moves. Over the next four moves — two for each side — the game can branch into 914,790 different games. Those games reach 307,713 different positions: most positions can be reached in more than one way, 3 on average.

The Lichess opening list names 67 further lines after this position, such as Giuoco Pianissimo (4. O-O Bc5 5. Nc3 d6 6. d3) and Knight Attack (4. Ng5).

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. Bc4 Nf6, which starts as the Zukertort Opening.