Colle System: Rhamphorhynchus Variation

1.Nf3 c5 2.e3 g6 3.d4 Bg7 4.dxc5 Qa5+

ECO A04

The Colle System: Rhamphorhynchus Variation is a chess opening reached after 1.Nf3 c5 2.e3 g6 3.d4 Bg7 4.dxc5 Qa5+, catalogued under code A04 in the Encyclopaedia of Chess Openings (ECO).

The defining move Qa5+ is chosen by Black on move 4.

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• Catalan Opening
• King's Indian Defense with ...e5

Every chess term used here is defined in the chess terms glossary. Browse all opening courses or the full ECO code index.