ECO B27 · Pterodactyl Defense

Pterodactyl Defense: Western, Rhamphorhynchus

1. e4 c5 2. Nf3 g6 3. d4 Bg7 4. dxc5 Qa5+

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

5. c3+0.68

White is slightly better. Stockfish 18, depth 18.

Analyze this position

In the Pterodactyl Defense: Western, Rhamphorhynchus (B27), reached after 1. e4 c5 2. Nf3 g6 3. d4 Bg7 4. dxc5 Qa5+, Stockfish 18 recommends 5. c3 for White. White is slightly better (+0.68).

Top engine moves

  1. +0.685. c3 Qxc5 6. Na3 d6 7. Be3 Qa5 8. Nc4 Qc7 9. Nd4 Nc6
  2. +0.505. Bd2 Qxc5 6. Nc3 Nc6 7. Nd5 Nf6 8. Nc7+ Kd8 9. Nxa8 Nxe4
  3. +0.365. Qd2 Qxc5 6. Nc3 b6 7. Bd3 Bb7 8. O-O Nf6 9. Qf4 O-O

Frequently asked questions

What is the best move in the Pterodactyl Defense: Western, Rhamphorhynchus?
After 1. e4 c5 2. Nf3 g6 3. d4 Bg7 4. dxc5 Qa5+, Stockfish 18 at depth 18 recommends 5. c3 for White, continuing Qxc5 6. Na3 d6 7. Be3 Qa5 8. Nc4 Qc7 9. Nd4 Nc6. White is slightly better (+0.68). The next best moves are 5. Bd2 (+0.50) and 5. Qd2 (+0.36).
Is the Pterodactyl Defense: Western, Rhamphorhynchus a good opening?
Stockfish rates the position at +0.68: 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 Pterodactyl Defense: Western, Rhamphorhynchus?
B27. ECO codes classify chess openings from A00 to E99; B is the volume for semi-open games (other than the French).

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