The Open Defense is a variation of the Catalan Opening, catalogued as ECO E03. The line runs 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+ Nbd7 6. Qxc4, reaching the position shown below after 11 half-moves.
White holds the centre with pawns on d4. Development is level at one minor pieces each. It is Black to move after six moves.
On the Catalan Opening generally: A sophisticated system combining Queen's Gambit ideas with a fianchettoed king's bishop.
You can play through this variation move by move in your browser — Learn mode walks the line with an explanation at each step, and Drill mode replays it from memory so you find out whether you actually know it. No account is required.
See all 26 Catalan Opening variations →
The Open Defense goes 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+ Nbd7 6. Qxc4. It is a variation of the Catalan Opening and is catalogued as ECO E03.
The Open Defense is ECO E03. ECO codes group openings by their move order, so nearby codes cover closely related lines of the Catalan Opening.
Stockfish evaluates the position after 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2 dxc4 5. Qa4+ Nbd7 6. Qxc4 at +0.23 at depth 18, which is balanced. Engine evaluation is only a starting point — at club level the practical value of a line is mostly about whether you know its plans better than your opponent does.
White holds the centre with pawns on d4. Development is level at one minor pieces each. It is Black to move.