ECO B06 · Pterodactyl Defense

Pterodactyl Defense: Western, Anhanguera

1. e4 g6 2. d4 Bg7 3. Nf3 c5 4. Be3 Qa5+

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

5. Nc3+0.81

White is clearly better. Stockfish 18, depth 18.

Analyze this position

In the Pterodactyl Defense: Western, Anhanguera (B06), reached after 1. e4 g6 2. d4 Bg7 3. Nf3 c5 4. Be3 Qa5+, Stockfish 18 recommends 5. Nc3 for White. White is clearly better (+0.81).

Top engine moves

  1. +0.815. Nc3 d6 6. Qd2 cxd4 7. Bxd4 Bxd4 8. Nxd4 Nf6 9. Nb3 Qb6
  2. +0.415. c3 Nf6 6. e5 Nd5 7. Bd2 O-O 8. c4 Nb4 9. dxc5 d6
  3. +0.415. Qd2 Qxd2+ 6. Nbxd2 cxd4 7. Nxd4 Nc6 8. N2b3 d6 9. f3 Bd7

Frequently asked questions

What is the best move in the Pterodactyl Defense: Western, Anhanguera?
After 1. e4 g6 2. d4 Bg7 3. Nf3 c5 4. Be3 Qa5+, Stockfish 18 at depth 18 recommends 5. Nc3 for White, continuing d6 6. Qd2 cxd4 7. Bxd4 Bxd4 8. Nxd4 Nf6 9. Nb3 Qb6. White is clearly better (+0.81). The next best moves are 5. c3 (+0.41) and 5. Qd2 (+0.41).
Is the Pterodactyl Defense: Western, Anhanguera a good opening?
Stockfish rates the position at +0.81: white is clearly 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, Anhanguera?
B06. 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+).