ECO A13 · English Opening

English Opening: Agincourt Defense, Catalan Defense, Semi-Slav Defense

1. c4 e6 2. Nf3 Nf6 3. g3 d5 4. Bg2 c6

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White to move. The arrow shows Stockfish’s best move.
Best move

5. b3+0.48

White is slightly better. Stockfish 18, depth 18.

Analyze this position

In the English Opening: Agincourt Defense, Catalan Defense, Semi-Slav Defense (A13), reached after 1. c4 e6 2. Nf3 Nf6 3. g3 d5 4. Bg2 c6, Stockfish 18 recommends 5. b3 for White. White is slightly better (+0.48).

Top engine moves

  1. +0.485. b3 d4 6. O-O c5 7. Re1 Nc6 8. e3 Be7 9. exd4 cxd4
  2. +0.455. d4 dxc4 6. Ne5 Bb4+ 7. Bd2 Qxd4 8. Bxb4 Qxe5 9. Ba3 b5
  3. +0.295. O-O dxc4 6. a4 Nbd7 7. Na3 Bxa3 8. Rxa3 e5 9. Qc2 O-O

Frequently asked questions

What is the best move in the English Opening: Agincourt Defense, Catalan Defense, Semi-Slav Defense?
After 1. c4 e6 2. Nf3 Nf6 3. g3 d5 4. Bg2 c6, Stockfish 18 at depth 18 recommends 5. b3 for White, continuing d4 6. O-O c5 7. Re1 Nc6 8. e3 Be7 9. exd4 cxd4. White is slightly better (+0.48). The next best moves are 5. d4 (+0.45) and 5. O-O (+0.29).
Is the English Opening: Agincourt Defense, Catalan Defense, Semi-Slav Defense a good opening?
Stockfish rates the position at +0.48: white is slightly better. Evaluations this early in the game are small, so practical results depend far more on knowing the plans and typical structures than on the engine's number.
What is the ECO code of the English Opening: Agincourt Defense, Catalan Defense, Semi-Slav Defense?
A13. ECO codes classify chess openings from A00 to E99; A is the volume for flank openings.

Opening names from the Lichess opening book (CC0). Pieces by Colin M.L. Burnett (GPLv2+).