Queen's Gambit Declined: Semi-Tarrasch Defense is a chess opening with the ECO code D41, part of the Queen's Gambit Declined family. It goes 1. c4 c5 2. Nf3 Nf6 3. Nc3 Nc6 4. g3 d5 5. d4 e6. White opens with 1. c4 (the English move) and Black answers 1... c5. After 10 moves it is White to move. The lesson on the board explains every move of the line and lets you play it yourself; it is free.
The moves
1. c4 – White plays the pawn to c4
1... c5 – Black plays the pawn to c5
2. Nf3 – White plays the knight to f3
2... Nf6 – Black plays the knight to f6
3. Nc3 – White plays the knight to c3
3... Nc6 – Black plays the knight to c6
4. g3 – White plays the pawn to g3
4... d5 – Black plays the pawn to d5
5. d4 – White plays the pawn to d4
5... e6 – Black plays the pawn to e6
About the Queen's Gambit Declined
After 1.d4 d5 2.c4, Black keeps the d5 pawn with ...e6 instead of taking on c4. It is solid, classical and very reliable.
Black develops calmly: ...Nf6, ...Be7, ...O-O, and keeps a strong pawn on d5.
The light-squared bishop on c8 is often stuck behind e6; freeing it is a main task.
Black frees the position with the breaks ...c5 or ...e5; White often plays for a minority attack with b4-b5.