Caissa Codex
A28

English Opening: King's English Variation, Four Knights Variation, Flexible Line 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 English Opening: King's English Variation, Four Knights Variation, Flexible Line

Play White's moves of the line from memory — 1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. d3 — and the trainer plays Black's replies; "Play the other side" turns it around.

Read about the line, its statistics on Lichess and Stockfish's evaluation on the English Opening: King's English Variation, Four Knights Variation, Flexible Line page, or pick another opening in the opening trainer.

https://chesscodex.org/train/english-opening-kings-english-variation-four-knights-variation-flexible-line