Catalan Opening: Open Defense is a chess opening with the ECO code E04, part of the Catalan Opening family. It goes 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. g3 c6 5. Bg2 dxc4. White opens with 1. d4 (the queen's pawn) and Black answers 1... Nf6. After 10 moves it is White to move. After the last move Black is a pawn ahead in material. The lesson on the board explains every move of the line and lets you play it yourself; it is free.
The moves
1. d4 – White plays the pawn to d4
1... Nf6 – Black plays the knight to f6
2. c4 – White plays the pawn to c4
2... e6 – Black plays the pawn to e6
3. Nf3 – White plays the knight to f3
3... d5 – Black plays the pawn to d5
4. g3 – White plays the pawn to g3
4... c6 – Black plays the pawn to c6
5. Bg2 – White plays the bishop to g2
5... dxc4 – Black captures on c4 with the d-pawn
About the Catalan Opening
White combines d4 and c4 with g3 and Bg2. The bishop on the long diagonal puts long-term pressure on Black's queenside.
The Bg2 bishop aims at b7 and a8; it is White's key piece.
If Black takes ...dxc4, White often gives the pawn for a while, then wins it back with Qc2 or Qa4.
Black wants ...c5 or ...e5 to free the position and the c8 bishop.