Caissa Codex
C42

Petrov's Defense: Classical Attack, Closed Variation trainer

Back to the opening, all openings to practise or my repertoire

Type a move and press Enter: e4, Nf3, O-O, or from and to squares like g1f3 (e7e8q to promote). The board is also played with the mouse.

Practise the Petrov's Defense: Classical Attack, Closed Variation

Play Black's moves of the line from memory — 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 Nf6 — and the trainer plays White's replies; "Play the other side" turns it around.

Read about the line, its statistics on Lichess and Stockfish's evaluation on the Petrov's Defense: Classical Attack, Closed Variation page, or pick another opening in the opening trainer.

https://chesscodex.org/train/petrovs-defense-classical-attack-closed-variation