I just thought that it would be helpful to have my own variation of the QGA and the QGD. So I will post it. First is the QGD that moves into the semi-slav.
1 d4…d5 2 c4…c6 3 Nc3…e6 4 e4 (The Knight on c3 protects the e4 pawn, the Bishop on f1 protects the c4 pawn and the Queen on d1 protects the d4 pawn even though the d4 pawn doesn’t need protection through most of the opening.) The point of this move is to apply pressure on d5. If white were to win d5 with out any threats from the c6 and e6 pawns, there would be no question about who had the superior position (for those that need it spelled out, white is superior with far greater development and center control) 4 … Nf6 5 Bf4 (attacking the knight on b8 and guarding the important d6 square ( if black were to put his bishop on the d6 square the important a3-f8 and b8-h2 diagonals would be black’s)) 5…Nbd7 6 Nf3…g6 7 Be2…Bg7 8 0-0 …0-0 9 Qd3 (Black can only watch in dread as white makes the Alekhine’s gun only with the Queen in the front and not the rear) 9…Ng4. Here is where I end on the QGD. Now here is the QGA.
1 d4…d5 2 c4…dxc4 (although I would not normally take the c4 pawn as black as white has the superior position.) 3 Nf3 (the black pawn is not going anywhere!) 3…Nf6 (It would be unwise to try to hold the c4 pawn as black. Be6 protects the pawn but it blocks the e pawn for black and it forces black to fianchetto in order to castle Kingside.) 4 e3 (builds a pawn chain and attacks the pawn on c4 with the bishop on f1) 4…Bf5 5 Nc3…Nc6 6 Bxc4…Bb4 (Pins white’s knight but white has a solution to this minor problem.) 7 0-0…0-0 (black quickly follows suit as not to fall behind in development.) 8 Bd2…Qd6 (this time it is black preparing for the Alekhine’s gun but, through pure coincidence, the Queen takes the nose again!) 9 Bb5…Rd8. This is followed by Rd7 and then Rad8 (or R8d8).