The Open Defense is a variation of the Catalan Opening, catalogued as ECO E04. The line runs 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 c6 5. Bg2 dxc4, reaching the position shown below after 10 half-moves.
White holds the centre with pawns on d4. Development is level at two minor pieces each, and Black is up a pawn of material. It is White to move after five moves. Black has doubled pawns on the c-file.
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. Nf3 d5 4. g3 c6 5. Bg2 dxc4. It is a variation of the Catalan Opening and is catalogued as ECO E04.
The Open Defense is ECO E04. 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. Nf3 d5 4. g3 c6 5. Bg2 dxc4 at +0.34 at depth 18, which is a slight pull for White, within normal opening margins. 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 two minor pieces each, and Black is up a pawn of material. It is White to move. Black has doubled pawns on the c-file.