Colle System: Siroccopteryx Variation

1. d4 g6 2. Nf3 Bg7 3. e3 c5 4. Bd3 cxd4 5. Nxd4 Qa5+

The Colle System: Siroccopteryx Variation is a chess opening classified as ECO A40, reached after 1. d4 g6 2. Nf3 Bg7 3. e3 c5 4. Bd3 cxd4 5. Nxd4 Qa5+. It is a line of the Colle System. White is to move.

This exact move order didn't appear in our sample of 12.6 million Lichess games: it's a rare line.

Engine evaluation: +0.13 (Stockfish, depth 34; best line 6. Bd2 Qd8 7. O-O Nc6 8. h3 d5)

ECO

A40

Moves

10 plies

FEN

rnb1k1nr/pp1pppbp/6p1/q7/3N4/3BP3/PPP2PPP/RNBQK2R w KQkq - 1 6

PGN

1. d4 g6 2. Nf3 Bg7 3. e3 c5 4. Bd3 cxd4 5. Nxd4 Qa5+

Analyse with Stockfish · Board image (SVG) · Open on Lichess

Opening names and moves from the Lichess openings dataset; statistics from the Lichess open database, 2026-09 (CC0), sample of 12.6 million games, bots excluded; evaluations from Lichess cloud analysis (all CC0). Master games from The Week in Chess #920–#1664 by Mark Crowther, used with permission.