The Colle-Zukertort Attack

We begin with Black's natural central development and learn how the two bishops fit around our pawn chain. The main decisions concern the e5 square, the timing of c4 and the placement of our rooks. Some branches lead to exchanges and a queenless position; others keep attacking possibilities alive. We judge each change by the exact piece placement, keeping king safety and Black's central counterplay in view.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 e6 4.Bd3 c5 5.b3 Nc6 6.Bb2 cxd4 7.exd4 Be7 8.O-O O-O 9.Nbd2 b6 10.a3 Bb7 11.Qe2 Nh5 12.Qe3FreeLearn
2. Line 2… 9.Nbd2 a6 10.a3 b5 11.Qe2 Bd7 12.Ne5 Rc8 13.f4 Qb6 14.Kh1 Qa7 15.c3 Rfd8 16.f5 exf5 17.Nxd7 Nxd7 18.Bxf5Premium
3. Line 3… 6.Bb2 Be7 7.O-O O-O 8.Nbd2 b6 9.Ne5 Nb4 10.Be2 Ba6 11.c3 Bxe2 12.Qxe2 Nc2 13.Rac1Premium
4. Line 4… 9.Ne5 Nxe5 10.dxe5 Nd7 11.f4 f5 12.exf6 Nxf6 13.c4 Bb7 14.Qc2 h6 15.Rad1Premium
5. Line 5… 9.Ne5 Bb7 10.f4 Rc8 11.a3 Na5 12.Qe2 Ne4 13.Rad1Premium
6. Line 6… 11.a3 Qc7 12.Qe2 Bd6 13.Nxc6 Qxc6 14.dxc5 Bxc5 15.Bxf6 gxf6 16.Bxh7+ Kxh7 17.Qh5+ Kg7 18.Qg4+ Kh8 19.Rf3Premium
7. Line 7… 10.f4 Nb4 11.Be2 cxd4 12.exd4 Ne4 13.c3 Nc6 14.Nxe4 dxe4 15.Ng4 f5 16.Ne3 Bf6 17.Bc4 Qd7 18.d5 exd5 19.Nxd5 Kh8 20.Nxf6 Qxd1 21.Raxd1 Rxf6 22.Rd7Premium
8. Line 8… 7.O-O Qc7 8.dxc5 Bxc5 9.Nbd2 O-O 10.c4 dxc4 11.Nxc4 Rd8 12.Qe2Premium

Black's bishop on d6 gives the centre a more direct character and makes exchanges around e5 especially important. We learn to support an advanced knight, improve the queen and use a rook lift only when the centre allows it. The tactical branches require careful material counting, including positions where our attack compensates for a sacrificed piece. Development and calculation decide whether the kingside pressure becomes a lasting advantage.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 e6 4.Bd3 c5 5.b3 Nc6 6.Bb2 cxd4 7.exd4 Bd6 8.O-O O-O 9.Nbd2 b6 10.a3 Bb7 11.Ne5 Qc7 12.Qe2 Ne7 13.f4 b5 14.Rac1 a6 15.Rf3Premium
2. Line 2… 11.Ne5 Ne7 12.Qe2 Rc8 13.f4 Rc7 14.Rae1 Ne8 15.g4 f6 16.Rf3 g6 17.Rh3 Rc8 18.Ndf3 fxe5 19.fxe5 Bb8 20.Ng5Premium
3. Line 3… 8.O-O Qc7 9.c4 O-O 10.Nc3 dxc4 11.bxc4 Be7 12.d5 exd5 13.Nxd5 Nxd5 14.cxd5 Nb4 15.Be4Premium
4. Line 4… 6.Bb2 Bd6 7.O-O O-O 8.Nbd2 Re8 9.dxc5 Bxc5 10.c4 b6 11.a3 a5 12.Qc2 h6 13.cxd5 Nxd5 14.Ne4Premium
5. Line 5… 8.Nbd2 b6 9.Ne5 Bb7 10.a3 a5 11.f4 Ne7 12.Rf3Premium
6. Line 6… 11.f4 a4 12.Qf3 axb3 13.cxb3 Qe7 14.Qh3 cxd4 15.exd4 Bxa3 16.Bxa3 Rxa3 17.Rxa3 Qxa3 18.Nd7 Rc8 19.Nxf6+ gxf6 20.Nf3Premium
7. Line 7… 10.a3 Rc8 11.Qe2 Ne7 12.dxc5 Bxc5 13.b4 Bd6 14.Rad1Premium
8. Line 8… 10.a3 Ne7 11.Qe2 Qc7 12.f4 Ne4 13.dxc5 Nxc5 14.Bxh7+ Kxh7 15.Qh5+ Kg8 16.Rf3 f6 17.Rh3 Bxe5 18.fxe5 f5 19.Rf1 Ba6 20.Rf4 Ne4 21.Nxe4 dxe4 22.c4 Rad8 23.Rfh4 f4 24.Qh7+ Kf7 25.Qh5+ g6 26.Rxf4+ Ke8 27.Rxf8+ Kxf8 28.Qh8+ Ng8 29.Rh4Premium
9. Line 9… 8.Nbd2 Qe7 9.a3 e5 10.dxc5 Bxc5 11.b4 Bb6 12.b5 e4 13.bxc6 bxc6 14.Bxf6 gxf6 15.Be2 exf3 16.Nxf3 Kh8 17.Qd3Premium
10. Line 10… 11.b4 Bd6 12.c4 e4 13.Bxf6 Qxf6 14.Bxe4 dxe4 15.Nxe4 Bxh2+ 16.Nxh2 Qg6 17.Ng3Premium
11. Line 11… 9.a3 b6 10.Ne5 Bb7 11.f4 Nd7 12.Nxd7 Qxd7 13.dxc5 Bxc5 14.Rf3 f6 15.Rh3 g6 16.b4 Bd6 17.Qg4Premium
12. Line 12… 9.a3 cxd4 10.exd4 e5 11.dxe5 Nxe5 12.Bxe5 Bxe5 13.Re1 Ne4 14.Nxe4 Bxa1 15.Neg5 Qxa3 16.Bxh7+ Kh8 17.Ne5Premium

With Black's queenside knight on d7, we can establish a central knight and decide how to reinforce it. The f-pawn may support the outpost, but its advance also changes our king cover. We compare quiet development with sharper queen and rook activity, including concrete sacrifices when Black's defenders leave key squares. The aim is to connect the central structure with an attack that our pieces can actually sustain.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 e6 4.Bd3 c5 5.b3 Nbd7 6.Bb2 g6 7.O-O Bg7 8.c4Premium
2. Line 2… 6.Bb2 Be7 7.O-O O-O 8.Nbd2 b6 9.Ne5 Bb7 10.Qe2 Qc7 11.f4 Rac8 12.Rad1 Rfd8 13.f5 Bd6 14.fxe6 fxe6 15.Ndf3Premium
3. Line 3… 11.f4 Ne4 12.Nxd7 Qxd7 13.Nxe4 dxe4 14.Bc4 Bd5 15.dxc5 Bxc5 16.Rad1Premium
4. Line 4… 6.Bb2 b6 7.O-O Bb7 8.Ne5 a6 9.Nd2 b5 10.Nxd7 Qxd7 11.dxc5 Bxc5 12.Qf3Premium
5. Line 5… 6.Bb2 Bd6 7.O-O O-O 8.Nbd2 Re8 9.Ne5Premium
6. Line 6… 8.Nbd2 b6 9.Ne5 Bb7 10.f4 Qc7 11.Nxd7 Qxd7 12.dxc5 Bxc5 13.Bxf6 gxf6 14.Bxh7+ Kxh7 15.Qh5+Premium
7. Line 7… 11.Nxd7 Nxd7 12.dxc5 Nxc5 13.Bxh7+ Kxh7 14.Qh5+ Kg8 15.Bf6Premium
8. Line 8… 8.Nbd2 Qe7 9.Ne5 cxd4 10.exd4 Ba3 11.Bxa3 Qxa3 12.Qe2 b6 13.f4 Bb7 14.Rae1 Qxa2 15.Nxd7 Nxd7 16.f5Premium

Black sometimes develops without immediately challenging d4 with the c-pawn. That gives us more freedom, but it does not justify an automatic kingside assault. We examine mirrored fianchettos, bishop exchanges and a useful switch to c4 when central pressure offers more than a fixed formation. Our plans depend on which bishop remains active and whether the king has castled, so the same opening structure can lead to different middlegames.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 e6 4.Bd3 b6 5.b3 Bb7 6.Bb2 Nbd7 7.O-O Bd6 8.Ne5 O-O 9.Nd2 Qe7 10.Qf3 Ba3 11.Bxa3 Qxa3 12.Qh3Premium
2. Line 2… 7.O-O Be7 8.Nbd2 O-O 9.c4 c5 10.Rc1 Ne4 11.cxd5 exd5 12.Qe2 Nxd2 13.Qxd2Premium
3. Line 3… 5.b3 Ba6 6.Bxa6 Nxa6 7.O-O Be7 8.Qe2 Nb8 9.c4 O-O 10.Bb2Premium
4. Line 4… 4.Bd3 g6 5.b3 Bg7 6.Ba3 Nbd7 7.O-O c5 8.dxc5 Ne4 9.Nd4 Nexc5 10.Bb5 Qb6 11.c4Premium

Early queen checks and knight jumps ask us to adjust the move order while keeping a coherent centre. We learn to block checks with useful developing moves, challenge an advanced knight through its pawn support and choose bishop squares suited to the new structure. Some branches produce a rook lift; others call for patient central pressure. The common task is to answer the immediate threat without losing the purpose of our development.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 e6 4.Bd3 c5 5.b3 Ne4 6.O-O f5 7.c4 Be7 8.cxd5 exd5 9.Bb2Premium
2. Line 2… 5.b3 Qa5+ 6.c3 Nc6 7.O-O Be7 8.Bb2 O-O 9.Nbd2 Rd8 10.Qe2 Qc7 11.Rac1 b6 12.c4Premium
3. Line 3… 5.b3 cxd4 6.exd4 Bb4+ 7.c3 Bd6 8.O-O Nc6 9.Re1 b6 10.Ne5 Bb7 11.Bf4 O-O 12.Nd2 Rc8 13.Re3Premium
4. Line 4… 4.Bd3 Ne4 5.Nbd2 f5 6.Ne5 Qf6 7.Nxe4 fxe4 8.Be2 Nd7 9.f4 Nxe5 10.dxe5 Qh4+ 11.g3 Qh3 12.Bf1 Qf5 13.c4 c6 14.Bd2Premium

When Black develops the queenside bishop early, we can question it with a knight or gain space with pawns. Those tempi are valuable only if our centre and king remain secure. We follow the resulting bishop exchanges, altered kingside files and changes to the minor-piece balance. Several lines leave us with the bishop pair against two knights, where development and the timing of central exchanges matter more than the bishop pair alone.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 Bg4 4.Nbd2 e6 5.h3 Bh5 6.g4 Bg6 7.Ne5 Nbd7 8.h4 Bd6 9.h5 Be4 10.f3 Nxe5 11.dxe5 Bxe5 12.Rh3Premium
2. Line 2… 5.h3 Bf5 6.g4 Be4 7.g5 Nfd7 8.Nxe4 dxe4 9.Nd2 Qxg5 10.Nxe4 Qg6 11.Qf3Premium
3. Line 3… 4.Nbd2 Nbd7 5.h3 Bh5 6.g4 Bg6 7.Nh4 e5 8.Nxg6 hxg6 9.Bg2 c6 10.c4 exd4 11.exd4 dxc4 12.O-OPremium
4. Line 4… 3.e3 Bf5 4.Nh4 Bg4 5.f3 Bd7 6.f4 c5 7.Be2 Nc6 8.O-O Qb6 9.c3Premium
5. Line 5… 3.e3 c6 4.Nbd2 Bf5 5.Nh4 Bg6 6.Nxg6 hxg6 7.c4 e6 8.g3 Nbd7 9.Bg2 Bd6 10.O-O O-O 11.b3 e5 12.cxd5 cxd5 13.dxe5 Bxe5 14.Rb1Premium
6. Line 6… 2.Nf3 c6 3.e3 Bf5 4.Nh4 Be4 5.f3 e6 6.g3 Bg6 7.Nxg6 hxg6 8.Nd2 Bd6 9.f4 Nf6 10.Bg2Premium
7. Line 7… 4.Nh4 Be6 5.Bd3 g6 6.O-O Bg7 7.Nd2 Nd7 8.c3 Ngf6 9.f4Premium

A kingside fianchetto changes the central decisions before our familiar bishop arrangement is complete. We challenge d5 with c4, develop securely and compare the consequences of different recaptures. Black's long-diagonal bishop becomes stronger when central pawns disappear, while our own bishop pair may benefit from the same opening of lines. We therefore judge exchanges by the resulting activity and king safety, including a queenless branch with central pawn play.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 g6 4.c4 Bg7 5.cxd5 O-O 6.Be2 Nxd5 7.e4 Nb6 8.O-O Bg4 9.Nbd2 e5 10.dxe5 Nc6 11.h3 Be6 12.Nb3Premium
2. Line 2… 4.c4 c6 5.Nc3 Bg7 6.Be2 O-O 7.O-O dxc4 8.Bxc4 Bg4 9.Be2 Nbd7 10.h3 Bxf3 11.Bxf3 e5 12.dxe5 Nxe5 13.Be2 Qxd1 14.Rxd1 Rfd8 15.Rxd8+ Rxd8 16.e4Premium

Black's early c-pawn challenge gives us a concrete choice between recovering a familiar centre and holding queenside space after a capture. We learn how pawn chains can be supported, undermined or exchanged while our pieces develop. The queen-check branches require precise tactics against exposed queens and invading knights. We keep the material count clear and finish development, so a temporary extra pawn does not distract us from the initiative.

1. Line 11.d4 d5 2.Nf3 Nf6 3.e3 c5 4.dxc5 e6 5.b4 a5 6.c3 axb4 7.cxb4 b6 8.Bb5+ Bd7 9.Bxd7+ Nbxd7 10.a4 bxc5 11.b5 c4 12.Nd4 Nc5 13.O-O Bd6 14.Nc3 Qc7 15.h3Premium
2. Line 2… 4.dxc5 Qa5+ 5.Nbd2 Nc6 6.a3 g6 7.Be2 Bg7 8.b4 Nxb4 9.Nb3 Nxc2+ 10.Kf1 Qc3 11.Rb1 Ne4 12.Bd3Premium
3. Line 3… 5.Nbd2 Qxc5 6.a3 g6 7.c4 Bg7 8.b4 Qc7 9.Bb2 O-O 10.Rc1 dxc4 11.Bxc4 Qb6 12.Qb3Premium
4. Line 4… 4.dxc5 Nc6 5.c3 a5 6.Bb5 e6 7.b4 Bd7 8.Qb3 b6 9.Bxc6 Bxc6 10.b5 a4 11.Qb2Premium

Black can bring the queenside bishop out before developing either knight. We use central pawn breaks and purposeful piece attacks to question that move order. The resulting positions can be sharp: queen activity, bishop exchanges and an uncastled king demand concrete calculation. We study how development creates compensation and when an exposed enemy queen gives us time to coordinate, while keeping the distinction between active play and a secure king clear.

1. Line 11.d4 d5 2.Nf3 Bg4 3.Ne5 Bh5 4.Qd3 Qc8 5.c4 f6 6.g4 fxe5 7.gxh5 dxc4 8.Qxc4 exd4 9.Nd2 Nc6 10.Ne4Premium
2. Line 2… 3.Ne5 Bf5 4.c4 e6 5.Nc3 c6 6.cxd5 exd5 7.e4 Be6 8.exd5 Bxd5 9.Nxd5 Qxd5 10.Bc4 Qxg2 11.Ke2 Qe4+ 12.Be3Premium
3. Line 3… 2.Nf3 Bf5 3.c4 e6 4.Qb3 Nc6 5.Bd2 Rb8 6.e3 Nf6 7.Nc3 Be7 8.Nh4 Be4 9.cxd5 exd5 10.f3 Bg6 11.Nxg6 hxg6 12.O-O-OPremium

Black's early knight on c6 blocks the c-pawn and gives us a reason to challenge d5. We compare a bishop pin with direct central pressure, then follow the consequences of doubled pawns and active queens. Some branches offer an extra pawn but require a safe queen retreat. We finish development and assess the minor-piece balance, so the structural targets are treated as practical opportunities rather than automatic proof of an advantage.

1. Line 11.d4 d5 2.Nf3 Nc6 3.e3 Bg4 4.Bb5 e6 5.Nbd2 Bd6 6.c4 dxc4 7.Bxc6+ bxc6 8.Qa4 Ne7 9.Qxc4 O-O 10.O-OPremium
2. Line 2… 3.e3 Nf6 4.c4 Bg4 5.Qb3 Bxf3 6.Qxb7 Nxd4 7.exd4 Bg4 8.Nc3 Rb8 9.Qxa7 Ra8 10.Qb7 Rb8 11.Qa6Premium

Different second moves can change the usual Colle move order and produce an open centre much sooner. We learn to answer those changes through active development, clear recapture choices and pressure on central pawn targets. One branch contains a fully concrete mating attack; another simplifies to a balanced queenless position despite an extra pawn. The contrast shows why tactics and the resulting pawn structure must guide our evaluation of each line.

1. Line 11.d4 d5 2.Nf3 e6 3.e3 c5 4.b3 Nc6 5.Bd3 cxd4 6.exd4 Bb4+ 7.c3 Bd6 8.O-O Nge7 9.Re1 O-O 10.c4 b6 11.Nc3 Bb7 12.Bxh7+ Kxh7 13.Ng5+ Kg6 14.h4 Rh8 15.Qg4 f5 16.Rxe6#Premium
2. Line 2… 2.Nf3 c5 3.dxc5 e6 4.e4 Bxc5 5.exd5 exd5 6.Bb5+ Nc6 7.O-O Nf6 8.Nc3 O-O 9.Bg5 Be7 10.Bxf6 Bxf6 11.Qxd5 Bxc3 12.Qxd8 Rxd8 13.bxc3Premium

When Black begins with a kingside knight and a queenside fianchetto, the d-pawn may remain flexible for several moves. We build our two-bishop arrangement, then choose central or queenside space according to Black's pawn commitments. The open e-file and possible c-file exchanges give the rooks clear roles. We also examine patient knight rerouting, keeping enough central control that a wing advance does not hand Black an easy counterbreak.

1. Line 11.d4 Nf6 2.Nf3 e6 3.e3 b6 4.Bd3 Bb7 5.O-O c5 6.b3 Be7 7.Bb2 O-O 8.Nbd2 Nc6 9.a3 Rc8 10.Qe2 Qc7 11.c4 d5 12.cxd5 exd5 13.Rac1Premium
2. Line 2… 8.Nbd2 cxd4 9.exd4 Nc6 10.a3 Re8 11.Re1 Bf8 12.Ne4 Nxe4 13.Bxe4 d5 14.Bd3 g6 15.h4 Bg7 16.Qd2Premium
3. Line 3… 9.exd4 d6 10.c4 Nbd7 11.Re1 Re8 12.Rc1 Rc8 13.b4 Rc7 14.Nb1 Bf8 15.Nc3 a6 16.Bf1Premium

Black's f-pawn advance creates kingside space while leaving central decisions open. We answer with a direct d-pawn advance, then adapt our bishops to the resulting structure instead of forcing the usual Colle placement. The queen must retreat safely when attacked, and a kingside fianchetto can support later central play. We complete development and challenge d5 with c4, keeping the king's safety connected to the opening of the centre.

1. Line 11.d4 e6 2.Nf3 f5 3.d5 exd5 4.Qxd5 d6 5.g3 Nf6 6.Qb3 Na6 7.Be3 d5 8.Bg2 c6 9.c4Premium