Semi-Slav Defense: Main Line is a chess opening with the ECO code D45, part of the Semi-Slav Defense family. It goes 1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. e3 e6 5. Nf3. White opens with 1. d4 (the queen's pawn) and Black answers 1... d5. After 9 moves it is Black 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. d4 – White plays the pawn to d4
1... d5 – Black plays the pawn to d5
2. c4 – White plays the pawn to c4
2... c6 – Black plays the pawn to c6
3. Nc3 – White plays the knight to c3
3... Nf6 – Black plays the knight to f6
4. e3 – White plays the pawn to e3
4... e6 – Black plays the pawn to e6
5. Nf3 – White plays the knight to f3
In chessGM's opening book this position continues with 5... Nbd7.
About the Semi-Slav Defense
Black combines ...c6 and ...e6 against the Queen's Gambit, making a solid triangle around d5. Some lines, like the Meran and Botvinnik, are very sharp.
Black can take on c4 with ...dxc4 and hold the pawn with ...b5.
The freeing breaks are ...c5 and ...e5.
The c8 bishop often goes to b7 after ...b5 or ...b6.
chessGM