In the Vienna Variation Black immediately goes for complications. He takes on c4 and gives White the chance to occupy the centre with a second pawn by e2-e4.The counter he plans is to put his dark-squared bishop on b4 and to attack the white centre with … c7-c5. Instead of 5. e2-e4 White has the quieter continuation of 5. e2-e3 and taking the pawn on c4 with his bishop.. Check with the queen from a4 is also worth considering for move 5.
In the Ragozin Variation Black develops his dark-squared bishop to b4 and pins the knight on c3, similarly to the Nimzo-Indian Defence. But since Black has already played ...d7-d5 White has no need to worry about possible doubled pawns in the event of an exchange on c3 since at any time he can take on d5 with his c-pawn. The main variations contain the counter-pin on the f6-knight by means of 5.Bc1-g5 after White has first exchanged pawns on d5.
Queen's Gambit Declined - Main Variation:
In the main variation Black develops his bishop to e7 and prepares to castle kingside. That is a very important position in chess theory. White now develops his dark-squared bishop to g5 or f4 and afterwards takes care of the development of his kingside. Black does the opposite. After he has developed his kingside he gradually brings into play the pieces on the queenside. The light-squared bishop on c8 is often fianchettoed to b7 or developed along the c8-h3 diagonal if White exchanges pawns on d5.
Main variations with 4.Bg5 Be7 5.Nf3
The Lasker Defence is an example of how things can continue in the Queen's Gambit Declined. With his last move Black in principle forces the exchange of two minor pieces and thus relieves his defence. The manoeuvre can be traced back to the first and only German world champion, Emanuel Lasker..
White does not play 4.Bg5
The Exchange Variation:
In the Exchange Variation White releases the central tension too soon. There now ensues an asymmetrical pawn structure. White would subsequently like to play the so-called 'minority attack' with b2-b4-b5 and b5xc6 which leaves Black with a weak pawn on c6. Black defends with an attack on the kingside with moves such as f7-f5 and Nf6-e4.
Orthodox Defence - struggle for a tempo:
In the struggle for a tempo in this variation White delays as long as possible the development of his Bf1-d3 as he waits for Black to play …. d5xc4. Then the bishop could get to c4 from f1 in a single move with Bf1xc4 instead of Bf1-d3xc4. White would have gained a tempo for his development.
Capablanca's relieving manoeuvre :
Capablanca's relieving manoeuvre solves the problem of the development of Black's queen's bishop by the freeing move 12... e6-e5. However, after 13.dxe5 Nxe5 14.Nxe5 Qxe5 15.f4 White can set his kingside pawn majority rolling forward.
Here the black queen's bishop is developed by fianchetto to b7. This system of the Queen's Gambit is considered very solid and Black retains counterplay. A disadvantage of the move … b6 is a slight weakening of the light squares on the queenside. White will continue with cxd5 in order to open the c-file.
Black plays 4.... Nbd7
Cambridge Springs Variation:
In the Cambridge Springs Variation Black delays the development of his king's bishop in order to gain time for a counter-attack by pinning the knight on c3. The best move is now 7.Nf3-d2. If White stereotypically plays 7.Bf1-d3 he is faced with the unpleasant 7... Nf6-e4!
Queen's Gambit Declined - Exchange Variation:
In the Exchange Variation White exchanges the pawn on d5 and at first holds back with the development of the knight to f3. Instead he immediately pins the knight on f6 with 5. Bc1-g5 and keeps open the future development of his king's knight. He frequently puts the light-squared bishop on d3 and the king's knight on e2. Black quickly develops his dark-squared bishop and castles short.