Chess Opening Tutorial : Queen's Gambit Declined - 4.Bg5

Introduction

A popular response by Black to 1.d4 is the Queen's Gambit Declined (often abbreviated QGD) : 1.d4 d5 2.c4 e6. The game usually continues 3.Nc3 Nf6 (or 3...Be7, which often transposes to the same variations) 4.Bg5. The position is shown the diagram.

The move 4.Bg5 pins the Black Knight and threatens 5.cxd5 exd5 6.Bxf6 gxf6, ruining Black's Kingside. Black has three good replies.

• 4...Be7, known as the Orthodox Defense;
  
  
• 4...Nbd7, delaying the development of the Bf8 for a move or two. Black's move sets a trap which has claimed many victims: 5.cxd5 exd5 and now 6.Nxd5 loses to 6...Nxd5 7.Bxd8 Bb4+ 8.Qd2 Bxd2+ 9.Kxd2 Kxd8; and
  
  
• 4...c6, deferring all decisions about development.

• 4...c5, which is more complicated and riskier than the main lines: 5.cxd5 cxd4 6.Qxd4 Be7 (6...Nc6 7.Bxf6 Nxd4 8.Bxd8 Nc2+ 9.Kd1 Nxa1 10.Bh4 and White will win the Na1 with a good game) 7.e4; and
  
  
• 4...h6, which is bad because it fails to meet the threat 5.Bxf6.

Index: Chess Opening Tutorial : Queen's Gambit Declined - 4.Bg5

1. Introduction
2. Move orders e.g. 4.Nf3
3. 4.Bg5 Be7 5.Nf3 O-O 6.e3 h6 7.Bh4
4. 4.Bg5 Be7 5.Nf3 O-O 6.e3 h6 7.Bxf6 Bxf6
5. 4.Bg5 Be7 5.Nf3 O-O 6.e3 Nbd7
6. 4.Bg5 Be7 5.Nf3 O-O 6.e3 Nbd7 7.Rc1
7. 4.Bg5 Nbd7 5.Nf3
8. 4.Bg5 c6 5.Nf3 h6
9. 4.Bg5 c6 5.Nf3 dxc4
10. 4.Bg5 c6 5.cxd5 exd5