Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nf6/3. Nxe5/3...d6/4. Nf3/4...Nxe4/5. d4

= Petrov's Defense = The Classical Attack in the Petrov is the most popular continuation to Black's natural 4...Nxe4. The overwhelmingly popular 5...d5 defends the knight and defends the center; White will attempt to attack Black's e4 knight and attack Black's d5 pawn with Bd3 and c4 respectively while Black will defend against White's ideas with all their might.

As mentioned above, 5...d5 is almost 20 times more popular than the second most popular move, 5...Be7, which often transposes into the main lines of the Classical Attack. Most Petrov lines have a higher than average draw percentage due to the highly symmetrical positions in the opening.

= Theory Table =

'''1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4'''