Italian Game:Two Knights Defense, Traxler Counterattack

Named after the Czech priest Karel Traxler, who played it in 1890; also called the Wilkes-Barre Variation. Black ignores the attack on f7 and counterattacks with 4...Bc5.

It is reached after 8 moves: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 Bc5. It is a line of the Italian Game.

White is to move and has 38 legal moves. Over the next four moves — two for each side — the game can branch into 1,583,482 different games. Those games reach 500,539 different positions: most positions can be reached in more than one way, 3.2 on average.

The Lichess opening list names 4 further lines after this position, such as Bishop Sacrifice Line (5. Bxf7+) and Knight Sacrifice Line (5. Nxf7).

The same moves can be played in 72 different legal orders that all reach this position. For example 1. Nf3 e5 2. e4 Nc6 3. Bc4 Nf6 4. Ng5 Bc5, which starts as the Zukertort Opening.