B06

Pterodactyl Defense: Western, Siroccopteryx

Chess diagram: Pterodactyl Defense: Western, Siroccopteryx after 5…Qa5+

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.

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Statistics from Lichess

4,054 games: White 35.3% / Draw 3.3% / Black 61.4%

The moves played next. Pick one to see it on the board.
Next moveGamesWhite / Draw / BlackW / D / B
1,8361,836
1,6611,661
541541
88
44
33
11

Rated Lichess games between players rated 1600 to 2500, from the Lichess opening explorer, updated Nov 3, 2026

Engine evaluation

+0.04 The position is about equal

Best play: 6. c3 Nf6 7. Qe2 O-O 8. O-O Nc6 9. Re1 d6 10. h3 Bd7

Stockfish 19, depth 30, after the line's last move. Scores are in pawns, from White's side.

Overview

Pterodactyl Defense: Western, Siroccopteryx (ECO B06, Semi-Open Games) is a variation of the Modern Defense, reached after 1. e4 g6 2. Nf3 Bg7 3. d4 c5 4. Bc4 cxd4 5. Nxd4 Qa5+ (5 moves).

In 4,054 rated Lichess games between players rated 1600 to 2500, White won 35.3%, Black 61.4% and 3.3% were drawn. White's most played move here is 6. c3, in 45% of those games.

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How to play against the Pterodactyl Defense: Western, Siroccopteryx

The most played answer, 6. c3, also scores best for White: 42.4%, with White winning 40.3% and Black 55.5% of 1,836 games. Of the main answers, 6. Bd2 scores lowest: 30.9%. Stockfish's first choice is also 6. c3.

Main answers: those played in at least 5% of these games. Score: White's wins plus half the draws, in rated Lichess games between players rated 1600 to 2500. How to play against other popular openings

Cite this page

Caissa Codex. “Pterodactyl Defense: Western, Siroccopteryx (B06)”. Lichess data as of 3 Nov 2026. https://chesscodex.org/openings/pterodactyl-defense-western-siroccopteryx