The Catalan Opening for White – the whole course to read – Learning studio

Starting position after 1.d4 Nf6 2.c4 e6 3.g3

The Catalan arises after 1.d4 Nf6 2.c4 e6 3.g3: you put the bishop on g2 and aim it down the long diagonal to a8. From there it presses on d5, c6 and b7 – Black often struggles to develop his queenside. The course is built from 3610 master games and checked by Stockfish. It suits you if you like calm positional play: you sometimes give the pawn on c4 for time and pressure and win it back later with the queen. Black mostly answers 3...d5 (a little over three games in four), less often 3...Bb4+ (about one game in six). After 3...d5 4.Bg2 there are two main roads: the closed system with 4...Be7 and the open one with 4...dxc4, where Black takes the pawn at once. After 3...Bb4+ you play 4.Bd2 and often reach the same positions. Stockfish sees you slightly better almost everywhere – nothing big, but lasting and pleasant to play.

The ideas

The bishop on g2 is your key piece: it aims through d5 and c6 to a8. Every time the long diagonal opens – for example with Ne5 – the pressure on b7 and a8 grows.
When Black takes on c4, you usually win the pawn back with the queen: Qc2 and Qxc4 or Qa4+ and Qxc4. There is rarely any hurry.
In the closed system you play Qc2, Rd1 and then the break e4: it opens the centre when your pieces are better placed.
Against b5 on the queenside you answer with a4 or b3 – you attack the advanced pawns instead of leaving them alone.
The bishop on d2 later looks for a better square: f4, a5 or g5. After Bf4 it is often chased with Nh5 – then you calmly retreat it to c1.

To the course with board, lines and training →

Chapter 1: 3…d5

Line 1: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Be4 11.Qc1 Bb7 12.Qc2

3…d5: The most common answer (77 % of games): Black builds a classic centre as in the Queen's Gambit. Now the bishop on g2 will aim at d5.
4.Bg2: The heart of the Catalan: the bishop stands on the long diagonal and presses on d5 and Black's queenside. You deliberately do not guard the pawn on c4 – if Black takes, you get time and pressure.
4…Be7: The closed system: Black develops calmly and castles first. He often takes on c4 only later.
5.Nf3: Normal development: the knight guards d4 and clears the way for castling. Later it can jump to e5 and open the bishop's diagonal.
5…O-O: Black castles – nearly every game goes this way.
6.O-O: You bring your king to safety too. You still leave the pawn on c4 unguarded: after dxc4 you win it back with Qc2.
6…dxc4: The main line (70 % of games): Black takes the pawn and wants to keep it with a6 and b5.
7.Qc2: The queen attacks c4. Black can only defend the pawn with a6 and b5 – but that weakens the a8–h1 diagonal, where your bishop is waiting.
7…a6: Black prepares b5 to hold the pawn on c4.
8.Qxc4: You take the pawn back at once. Stockfish rates a4, which stops b5, just as highly – with Qxc4 the game stays simpler, but Black gains space with b5.
8…b5: With tempo against your queen – and the bishop wants to go to b7.
9.Qc2: The queen goes back to c2, where she controls the b1–h7 diagonal and the c-file.
9…Bb7: The bishop opposes your bishop on g2. The long diagonal is now contested.
10.Bd2: The bishop wants to go to a5, where it cramps the queenside, or later via e1 and c3. Stockfish rates the position as level afterwards (−0.05) – you play for slow pressure, not for a quick advantage.
10…Be4: The most common move: Black attacks your queen and gains a tempo.
11.Qc1: The queen steps aside to c1 and stays on the c-file. From there she later supports Bf4 or Bg5.
11…Bb7: Black goes back and so offers a repetition. 82 % of these games ended in a draw.
12.Qc2: With Qc2 you repeat the position after Bd2 – if you want a draw, this is the easy way (91 % draws). Stockfish prefers Bf4 with Rd1 and Ne5 to keep playing. (transposition)

Line 2: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Be4 11.Qc1 Nbd7 12.Ba5 Rc8 13.Nbd2 Ba8 14.Qc2 Nb6 15.Qd3

up to 11.Qc1 as line 1

11…Nbd7: Black develops the knight but leaves the square c5 and the queenside a little weak.
12.Ba5: The bishop settles on a5: it eyes c7 and ties Black's pieces to the queenside. Nbd2 follows.
12…Rc8: The rook protects c7 and prepares c5.
13.Nbd2: You develop your last knight and question the bishop on e4. If it retreats, the diagonal is open again for your bishop on g2.
13…Ba8: The bishop retreats into the corner but stays on the long diagonal.
14.Qc2: The queen returns to c2 and controls the c-file and the square c6. Stockfish shows a3 and Bc3 as the plan, with a slight edge for you.
14…Nb6: From here Stockfish plays on alone (depth 30) – the games go no further. 14...Nb6 – from b6 the knight controls the squares c4 and d5.
15.Qd3: With 15.Qd3 the queen leaves the c-file, where the rook on c8 stands. Stockfish sees you slightly ahead (+0.21).

Line 3: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Be4 11.Qc1 Qc8 12.Bg5 c5 13.Nbd2 Bb7 14.dxc5 Qxc5 15.Qxc5

up to 11.Qc1 as line 2

11…Qc8: The queen prepares c5. All games in this course ended in a draw.
12.Bg5: The bishop attacks the knight on f6, which protects the bishop on e4.
12…c5: Black attacks your centre at once.
13.Nbd2: Stockfish's move: you question the bishop on e4. After Bb7 dxc5 Qxc5 Qxc5 Bxc5 a quiet endgame follows, in which Rfc1 gives you some pressure on the c-file.
13…Bb7: From here Stockfish plays on alone (depth 30) – the games go no further. The bishop drops back to b7.
14.dxc5: 14.dxc5 – you take on c5 and open the position.
14…Qxc5: Black recaptures on c5 and attacks your bishop on g5 – level, you have a little more space. Stockfish: level (+0.19).
15.Qxc5: With 15.Qxc5 you trade queens. In the endgame Black's pawns on a6 and b5 can become weaknesses – Stockfish sees you slightly ahead (+0.22).

Line 4: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Be4 11.Qc1 Qc8 12.Bg5 Nbd7 13.Nbd2 Bb7 14.Ne5 Bxg2 15.Kxg2

up to 12.Bg5 as line 3

12…Nbd7: Black guards the knight on f6 once more.
13.Nbd2: Stockfish's move: the bishop on e4 has to retreat, then Ne5 follows and the light-squared bishops come off.
13…Bb7: From here Stockfish plays on alone (depth 30) – the games go no further.
14.Ne5: 14.Ne5 – the knight goes into the centre and opens the diagonal of your bishop on g2 against b7.
14…Bxg2: Black trades the bishops.
15.Kxg2: After 15.Kxg2 your knight stands strongly on e5 and the position is quiet – Stockfish: level (+0.06).

Line 5: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Be4 11.Qc1 Nc6 12.Be3 Rc8 13.Nbd2 Bd5 14.Rd1 h6 15.Ne5

up to 11.Qc1 as line 4

11…Nc6: The knight wants to make pressure via b4 or a5.
12.Be3: The bishop guards d4, which the knight on c6 attacks, and keeps the square c5 under control.
12…Rc8: From here Stockfish plays on alone (depth 30) – the games go no further.
13.Nbd2: You develop the last knight and attack the bishop on e4.
13…Bd5: The bishop goes to d5 and offers a trade against your bishop on g2 – Black wants to close the long diagonal.
14.Rd1: The rook lines up behind the pawn on d4.
14…h6: Black takes g5 from your knight and gives his king air. Stockfish: level (0).
15.Ne5: With 15.Ne5 you attack the knight on c6 and open the diagonal against the bishop on d5. Stockfish: level (0).

Line 6: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Be4 11.Qc1 c6 12.a4 Nbd7 13.Nc3 Bg6 14.Nh4 Bh5 15.h3

up to 11.Qc1 as line 5

11…c6: Black supports the pawn on b5.
12.a4: 12.a4 – you attack the pawn on b5, the typical lever in the Catalan.
12…Nbd7: From here Stockfish plays on alone (depth 30) – the games go no further.
13.Nc3: The knight comes into play with tempo against the bishop on e4.
13…Bg6: The bishop steps aside to g6 and avoids the trade – it stays on the diagonal against c2.
14.Nh4: The knight chases the bishop on g6.
14…Bh5: The bishop goes to h5 and dodges the knight on h4. Stockfish: level (+0.03).
15.h3: With 15.h3 you make life hard for the bishop on h5 – you threaten to attack it with the g-pawn. Stockfish: level (+0.05).

Line 7: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Nc6 11.e3 Nb4 12.Bxb4 Bxb4 13.a3 Bd6 14.Nbd2 Rc8 15.e4

up to 10.Bd2 as line 6

10…Nc6: The knight attacks d4 and wants to go to b4 to harass your queen.
11.e3: You give d4 solid cover. If Nb4 comes, you simply exchange the knight.
11…Nb4: With tempo against your queen.
12.Bxb4: You exchange the annoying knight. Black gets the bishop pair, but you have a solid centre and then play a3 with tempo.
12…Bxb4: Black recaptures with the bishop and trades the dark bishop – the position is quiet. Stockfish: level (+0.03).
13.a3: The bishop must move, and you gain space on the queenside.
13…Bd6: The bishop aims at your kingside.
14.Nbd2: Stockfish's move: the knight supports the push e4. Stockfish shows Rc8 e4 Be7 e5 – you gain space in the centre.
14…Rc8: From here Stockfish plays on alone (depth 30) – the games go no further. Black puts the rook on the c-file.
15.e4: 15.e4 – you take the centre. You have space, Black has the bishop pair – Stockfish: level (+0.04).

Line 8: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Ra7 11.Rc1 Be4 12.Qb3 Nbd7 13.Ba5 Qb8 14.Qe3 Bd6 15.Nbd2

up to 10.Bd2 as line 7

10…Ra7: A special move: the rook guards the 7th rank and can later support c5.
11.Rc1: The rook takes the c-file opposite the pawn on c7 and gets ready for it to open.
11…Be4: Again against your queen.
12.Qb3: The queen goes to b3, where she attacks the pawn on b5 and eyes e6.
12…Nbd7: A little inaccurate (Stockfish wanted Nc6): now your bishop gets the square a5.
13.Ba5: The bishop settles on a5 and eyes b6 and c7. You are a little better.
13…Qb8: From here Stockfish plays on alone (depth 30) – the games go no further.
14.Qe3: The queen leaves b3 and goes to e3.
14…Bd6: The bishop goes to d6 and eyes h2 – Black has developed comfortably. Stockfish: level (+0.08).
15.Nbd2: With 15.Nbd2 you question the bishop on e4 and develop the last piece. Stockfish: level (+0.07).

Line 9: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O dxc4 7.Qc2 a6 8.Qxc4 b5 9.Qc2 Bb7 10.Bd2 Bd6 11.Re1 Be4 12.Qc1 Bb7 13.Qc2

up to 10.Bd2 as line 8

10…Bd6: The bishop goes to d6 and prepares castling.
11.Re1: The rook prepares the advance e2–e4.
11…Be4: The bishop attacks your queen on c2 and gains a tempo.
12.Qc1: The queen retreats to c1 and avoids the bishop.
12…Bb7: The moves repeat. By transposition the game goes on in a line the course already teaches.
13.Qc2: The queen returns to c2 – the moves repeat. Stockfish: level (0). (transposition)

Line 10: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O c6 7.Qc2 Nbd7 8.b3 b6 9.Rd1 Bb7 10.Nc3 Rc8 11.e4 dxe4 12.Nxe4 Nxe4 13.Qxe4 Ba8 14.Qe2 c5 15.dxc5

up to 6.O-O as line 9

6…c6: Black holds d5 firmly instead of taking – a solid bulwark.
7.Qc2: The queen guards c4 and prepares Rd1 and the break e4.
7…Nbd7: Black wants to develop the queenside with b6 and Bb7 or Ba6.
8.b3: You guard c4 once more and free b2 for the bishop. Now dxc4 is no longer an issue.
8…b6: Black wants to bring the bishop to b7 or a6.
9.Rd1: The rook takes the d-file opposite the black queen – important for the later break e4.
9…Bb7: The bishop takes its place behind the pawn chain c6–d5.
10.Nc3: The knight supports e4 – now you threaten to break open the centre.
10…Rc8: A little inaccurate (Stockfish wanted Re8): the rook leaves the defence of the centre. After e4 you are already clearly more comfortable (+0.5).
11.e4: The break: you open the centre while your rook is already on the d-file.
11…dxe4: Black takes and wants to simplify the centre.
12.Nxe4: The natural recapture. Stockfish also shows Ng5 with h6 Ngxe4 – but even after Nxe4 you keep a pleasant edge.
12…Nxe4: Black exchanges pieces to get more room.
13.Qxe4: Your queen is centralised, and the bishop on g2 aims at the pawn on c6. Black still has to prepare c5 – you are better (+0.42).
13…Ba8: From here Stockfish plays on alone (depth 30) – the games go no further. Black prepares 14...c5.
14.Qe2: The queen steps aside to e2.
14…c5: Black attacks your centre.
15.dxc5: With 15.dxc5 you open the d-file for your rook on d1. Stockfish sees you slightly ahead (+0.45).

Line 11: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O c6 7.Qc2 Nbd7 8.b3 b6 9.Rd1 Ba6 10.Nbd2 Rc8 11.e4 c5 12.exd5 exd5 13.Bb2 cxd4 14.Nxd4 b5 15.Nf5

up to 9.Rd1 as line 10

9…Ba6: The bishop attacks the pawn on c4 and wants to work around the pawn chain.
10.Nbd2: The knight gives c4 extra cover and supports e4.
10…Rc8: Too slow (Stockfish wanted c5 at once): now e4 comes with force, and you are clearly better (+0.5).
11.e4: The central break, well prepared by rook, queen and knight.
11…c5: Black strikes back in the centre.
12.exd5: You open the e-file and the diagonal of your bishop on g2. Black gets a pawn on d5 that comes under pressure.
12…exd5: Now the pawns on c5 and d5 are hanging.
13.Bb2: The bishop comes to the long a1–h8 diagonal and supports d4. Both bishops now aim into Black's position.
13…cxd4: Inaccurate (Stockfish wanted Re8): the centre opens in favour of your pieces – you are clearly better afterwards (+0.8).
14.Nxd4: The knight stands strongly on d4 and eyes the square f5. The pawn on d5 is isolated and becomes a target.
14…b5: Black looks for counterplay against c4.
15.Nf5: Stockfish's move: the knight attacks the bishop on e7 and the pawn on g7, which your bishop on b2 also targets. In Stockfish's line bxc4 bxc4 Re8 Bxd5 Nxd5 it even crashes in on g7.

Line 12: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O c6 7.Qc2 Nbd7 8.b3 b6 9.Rd1 Ba6 10.Nbd2 c5 11.e4 dxc4 12.Nxc4 cxd4 13.Nxd4 Rc8 14.e5 Nd5 15.Qb2

up to 10.Nbd2 as line 11

10…c5: Black attacks the centre.
11.e4: 11.e4 – you answer in the centre.
11…dxc4: From here Stockfish plays on alone (depth 30) – the games go no further.
12.Nxc4: The knight comes actively into play by taking on c4.
12…cxd4: Black trades on d4 and opens the diagonal of his bishop on a6.
13.Nxd4: The knight stands in the centre on d4.
13…Rc8: The rook goes to c8 and attacks your knight on c4.
14.e5: 14.e5 drives away the knight on f6.
14…Nd5: The knight jumps to d5 – a strong square in front of your isolated pawn on d4. Stockfish: level (0).
15.Qb2: With 15.Qb2 the queen leaves the c-file, where the rook on c8 stands. Stockfish: level (0).

Line 13: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O c6 7.Qc2 Nbd7 8.b3 b5 9.c5 Ne4 10.Bb2 a5 11.a3 h5 12.b4 h4 13.Ne5 Nxe5 14.dxe5 hxg3 15.hxg3

up to 8.b3 as line 12

8…b5: A mistake (Stockfish wanted b6): Black attacks, but hands you the square c5. After c5 Black's queenside is fixed (+0.77).
9.c5: You push past and close the queenside. The bishop on c8 stays locked behind its pawns, and you have space. Stockfish then plans Nc3 against Ne4.
9…Ne4: The knight occupies the hole on e4.
10.Bb2: The bishop goes to b2, supporting d4 and later b4. Stockfish prefers Nc3 to question the knight on e4 at once – but you are better either way.
10…a5: From here Stockfish plays on alone (depth 30) – the games go no further.
11.a3: 11.a3 prepares 12.b4 to support the pawn on c5.
11…h5: Black attacks your kingside with the h-pawn.
12.b4: 12.b4 gains space on the queenside and supports c5.
12…h4: 12...h4 attacks your kingside – Black wants to open the h-file.
13.Ne5: The knight goes to e5.
13…Nxe5: Black trades on e5 and takes the strong square from your knight.
14.dxe5: You recapture with the pawn and gain space.
14…hxg3: Black takes on g3 and opens the h-file – you stand slightly better. Stockfish: level (+0.18).
15.hxg3: After 15.hxg3 you have space on the queenside with the pawns on b4 and c5, while Black has counterplay on the kingside. Stockfish sees you slightly ahead (+0.29).

Line 14: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O c6 7.Qc2 b6 8.Nbd2 Bb7 9.e4 Na6 10.Rd1 Rc8 11.b3 c5 12.exd5 exd5 13.Bb2 Rc7 14.Rac1 Qa8 15.Qf5

up to 7.Qc2 as line 13

7…b6: Black wants to bring the bishop to b7 or a6 without first putting the knight on d7.
8.Nbd2: The knight supports c4 and e4. Stockfish prefers Rd1 with Nc3 and b3.
8…Bb7: The bishop takes its place behind the c6–d5 chain.
9.e4: The central break: you gain space, and the position becomes sharp. In Stockfish's line Black plays Na6 and c5.
9…Na6: The knight goes to a6 – via b4 it can come into play.
10.Rd1: The rook takes the d-file.
10…Rc8: From here Stockfish plays on alone (depth 30) – the games go no further.
11.b3: b3 wins back the pawn on c4 or opens the b-file – White releases the tension on the queenside.
11…c5: 11...c5 attacks the centre – the typical freeing move.
12.exd5: You exchange in the centre.
12…exd5: Black recaptures with the pawn and has a pawn on d5.
13.Bb2: The bishop comes to the long diagonal.
13…Rc7: The rook goes to c7 and wants to double the rooks.
14.Rac1: The rook goes to c1 against the rook on c7.
14…Qa8: The queen goes to a8 and presses on the long diagonal against e4. Stockfish: level (+0.18).
15.Qf5: With 15.Qf5 the queen takes an active post on the kingside. Black's pawns on c5 and d5 can become targets – Stockfish sees you slightly ahead (+0.16).

Line 15: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.Qc2 c6

up to 6.O-O as line 14

6…Nbd7: Black develops without committing himself.
7.Qc2: The queen guards c4. After c6 you are back in the system with Qc2 and Nbd7.
7…c6: Transposition: the position is the same as after c6 Qc2 Nbd7 – it goes on there with b3. (transposition)

Line 16: 3…d5 4.Bg2 Be7 5.Nf3 O-O 6.O-O Nbd7 7.Qc2 dxc4 8.Qxc4 c5 9.Rd1 Nb6 10.Qc2 Nbd5 11.dxc5 Qc7 12.Bg5 Qxc5 13.Qxc5 Bxc5 14.Ne5 Be7 15.Nc3

up to 7.Qc2 as line 15

7…dxc4: Taken too late: the queen is already in place, and Black has no time for a6 and b5. You are better (+0.55).
8.Qxc4: You have the pawn back and the better development. The bishop on c8 is still locked in.
8…c5: From here Stockfish plays on alone (depth 30) – the games go no further. Black attacks the centre at once.
9.Rd1: 9.Rd1 – the rook lines up on the d-file, a typical Catalan move.
9…Nb6: The knight attacks your queen on c4 and gains a tempo.
10.Qc2: The queen steps away from the knight.
10…Nbd5: The knight jumps to d5 – a strong square.
11.dxc5: You take the pawn on c5.
11…Qc7: The queen goes to c7 and wants the pawn on c5 back.
12.Bg5: The bishop attacks the knight on f6.
12…Qxc5: The queen recaptures on c5 and offers a queen trade.
13.Qxc5: You trade queens.
13…Bxc5: Black recaptures with the bishop – a quiet endgame.
14.Ne5: The knight goes to e5, and your bishop on g2 presses on d5.
14…Be7: The bishop retreats to e7 – you stand slightly better, your bishop on g2 is stronger. Stockfish sees you ahead (+0.31).
15.Nc3: With 15.Nc3 you attack the knight on d5 once more. In the endgame you have the more active pieces – Stockfish sees you slightly ahead (+0.41).

Line 17: 3…d5 4.Bg2 dxc4 5.Nf3 Nc6 6.Qa4 Bb4 7.Bd2 Nd5 8.Bxb4 Nxb4 9.O-O Rb8 10.Nc3 a6 11.Ne5 O-O 12.Nxc6 Nxc6 13.Bxc6 bxc6 14.Qxc4 Rxb2 15.Rab1 Rb6 16.Qc5

up to 4.Bg2 as line 16

4…dxc4: The open system: Black takes the pawn at once (41 % of games). You win it back later – development comes first.
5.Nf3: You develop and prepare Qa4+ or Ne5 to win back c4.
5…Nc6: The most active move: Black wants to hold the pawn or get counterplay with Bb4+ and Nd5.
6.Qa4: The queen pins the knight on c6 and attacks c4 at the same time. Black now has to deal with both.
6…Bb4: The main answer: Black develops with check and wants to trade bishops with Nd5.
7.Bd2: You block the check and offer the bishop trade.
7…Nd5: The knight guards the bishop on b4 and eyes b6 and e3.
8.Bxb4: You trade bishops. Afterwards the knight on b4 is a little loose, and you can castle in peace.
8…Nxb4: The knight threatens to jump to c2 – but once you castle that is no longer an issue.
9.O-O: The king is safe, and the rook on a1 is no longer exposed to Nc2. Now you calmly win back c4.
9…Rb8: The rook leaves your bishop's diagonal and prepares b5.
10.Nc3: Development and pressure on c4. Stockfish prefers Na3, heading straight for c4 – both roads lead to a small edge.
10…a6: Black guards the knight on b4 and prepares b5.
11.Ne5: The knight opens your bishop's diagonal and attacks c6 and c4. Now you get the pawn back.
11…O-O: Black castles and lets you win back the pawn.
12.Nxc6: You trade knights – then your bishop takes on c6 and the queen wins back c4.
12…Nxc6: The knight from b4 recaptures.
13.Bxc6: You give the bishop for the knight and wreck Black's pawn structure: after bxc6 Black has doubled pawns on the c-file.
13…bxc6: Now the pawn on c4 is hanging.
14.Qxc4: The pawn is back. Black takes b2 with Rxb2, but the pawns on a6, c6 and c7 stay weak.
14…Rxb2: The rook grabs the pawn on b2 – but on the 2nd rank it is also a target.
15.Rab1: You offer the rook trade and take the b-file.
15…Rb6: The rook steps back and guards the pawn on c6.
16.Qc5: The queen is active on c5, attacks the pawn on c6 and keeps Black's weak pawns tied down. Stockfish sees the position as nearly level, but Black has to defend precisely.

Line 18: 3…d5 4.Bg2 dxc4 5.Nf3 Nc6 6.Qa4 Bb4 7.Bd2 Nd5 8.Bxb4 Nxb4 9.O-O a6 10.Ne5 O-O 11.a3 Nxe5 12.dxe5 Nd5 13.Qxc4 Rb8 14.Qc2 Bd7 15.Rd1

up to 9.O-O as line 17

9…a6: A mistake (Stockfish wanted Rb8): the rook stays on a8 – on your bishop's diagonal. With Ne5 you are clearly better at once (+0.86).
10.Ne5: The trap: the knight unleashes the bishop on g2 and threatens to take on c6 – then the knight on b4 falls because nothing protects it any more. After O-O comes a3, and in Stockfish's line Nxe5 dxe5 Nd5 Qxc4 you win back the pawn with a clear edge.
10…O-O: From here Stockfish plays on alone (depth 30) – the games go no further. Black castles.
11.a3: 11.a3 attacks the knight on b4.
11…Nxe5: Black trades your strong knight on e5.
12.dxe5: You recapture with the pawn and gain space on the kingside.
12…Nd5: The knight jumps to d5 and blocks your bishop's diagonal.
13.Qxc4: You win back the pawn on c4.
13…Rb8: The rook goes to b8 and covers the pawn on b7.
14.Qc2: The queen goes to c2 and eyes h7.
14…Bd7: The bishop goes to d7 and connects the rooks – you stand better. Stockfish sees you ahead (+0.56).
15.Rd1: With 15.Rd1 you put the rook against the knight on d5. Your bishop on g2 presses on d5 and b7, and the pawn on e5 takes space from Black – Stockfish sees you clearly ahead (+0.73).

Line 19: 3…d5 4.Bg2 dxc4 5.Nf3 Nc6 6.Qa4 Bb4 7.Bd2 Bd6 8.Ne5 O-O 9.Nxc6 bxc6 10.Qxc4 Rb8 11.b3 Qe7 12.O-O Rd8 13.Bc3 Rb6 14.Ba5 Ba6 15.Qc2

up to 7.Bd2 as line 18

7…Bd6: Black avoids the bishop trade and keeps the bishop pair.
8.Ne5: The knight opens the diagonal and attacks c6 and c4. Stockfish prefers Na3 followed by Nxc4.
8…O-O: From here Stockfish plays on alone (depth 30) – the games go no further.
9.Nxc6: 9.Nxc6 – you trade the knight and spoil Black's pawns.
9…bxc6: Black recaptures with the b-pawn and has doubled pawns on the c-file.
10.Qxc4: You win back the pawn on c4.
10…Rb8: The rook goes to the half-open b-file.
11.b3: b3 wins back the pawn on c4 or opens the b-file – White releases the tension on the queenside.
11…Qe7: The queen goes to e7 and covers the pawn on c5.
12.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
12…Rd8: The rook goes to d8 and prepares e5.
13.Bc3: The bishop goes to b2 onto the long diagonal and covers d4.
13…Rb6: The rook goes to b6 and covers the pawn on c6. Stockfish: level (+0.07).
14.Ba5: The bishop attacks the rook on b6.
14…Ba6: Black attacks your queen.
15.Qc2: With 15.Qc2 the queen steps aside. Black has doubled pawns on the c-file – Stockfish: level (+0.05).

Line 20: 3…d5 4.Bg2 dxc4 5.Nf3 Nc6 6.Qa4 Nd7 7.Qxc4 Nb6 8.Qd3 e5 9.Nxe5 Nb4 10.Qc3 Qxd4 11.O-O Qxc3 12.Nxc3 Bd6 13.Nf3 c6 14.Ne4 Be7 15.Bf4

up to 6.Qa4 as line 19

6…Nd7: Inaccurate (Stockfish wanted Bb4+): Black gives back the pawn on c4 at once. After Qxc4 you stand comfortably (+0.47).
7.Qxc4: The pawn is back, and you have the centre and the strong bishop on g2.
7…Nb6: With tempo against your queen.
8.Qd3: The queen guards d4 and is safe. Stockfish prefers Qb5, which is more active and makes e5 harder.
8…e5: Black strikes in the centre and gives a pawn for it.
9.Nxe5: You take the pawn – but careful: now d4 is no longer guarded.
9…Nb4: With tempo: the knight attacks your queen and wants to jump to c2 with check.
10.Qc3: The queen guards c2 and stays on the diagonal to d4.
10…Qxd4: Black wins back the pawn and offers a queen trade.
11.O-O: You castle and allow the queen trade. In the endgame your bishop on g2 is especially strong.
11…Qxc3: The queens come off.
12.Nxc3: You recapture with development and cover the square d5.
12…Bd6: The bishop attacks the knight on e5.
13.Nf3: The knight retreats. In the endgame your pieces are better; Stockfish plans Rd1 and a3.
13…c6: From here Stockfish plays on alone (depth 30) – the games go no further.
14.Ne4: 14.Ne4 – the knight attacks the bishop on d6.
14…Be7: The bishop goes to e7 and avoids the knight – level. Stockfish: level (+0.17).
15.Bf4: With 15.Bf4 you develop the bishop and control the squares d6 and c7. Without queens you are the more active side – Stockfish sees you slightly ahead (+0.21).

Line 21: 3…d5 4.Bg2 dxc4 5.Nf3 Nc6 6.Qa4 Bd7 7.Qxc4 Na5 8.Qd3 c5 9.O-O Rc8 10.Be3 c4 11.Qc2 Be7 12.Rd1 Nc6 13.Nc3 Nb4 14.Qc1 O-O 15.Ne5

up to 6.Qa4 as line 20

6…Bd7: Black breaks the pin and wants to hold the pawn with Na5.
7.Qxc4: You win back the pawn at once.
7…Na5: With tempo against the queen – and the bishop on d7 wants to go to c6.
8.Qd3: The queen guards d4 and leaves c4. Stockfish prefers Qc3; both moves keep a small edge.
8…c5: Black attacks your centre.
9.O-O: King to safety first. After cxd4 Nxd4 your knight is centralised, and the bishop on g2 rules the diagonal.
9…Rc8: From here Stockfish plays on alone (depth 30) – the games go no further.
10.Be3: 10.Be3 attacks the pawn on c5.
10…c4: Black sidesteps with the pawn and attacks the queen.
11.Qc2: The queen goes to c2 and covers c4 and e4 – she prepares e4.
11…Be7: The bishop goes to e7 and prepares castling.
12.Rd1: The rook goes to d1 behind the pawn on d4.
12…Nc6: The knight comes to c6 and eyes b4 and d4.
13.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
13…Nb4: The knight attacks the queen on c2.
14.Qc1: The queen goes to c1 and avoids the knight.
14…O-O: Black castles – you stand slightly better. Stockfish sees you ahead (+0.31).
15.Ne5: With 15.Ne5 you attack the bishop on d7 and open the diagonal of the bishop on g2. Stockfish sees you slightly ahead (+0.39).

Line 22: 3…d5 4.Bg2 dxc4 5.Nf3 a6 6.O-O Nc6 7.e3 Bd7 8.Qe2 b5 9.Rd1 Be7 10.b3 cxb3 11.axb3 O-O 12.Nc3 Bd6 13.Bb2 h6 14.e4 e5 15.Nxb5

up to 5.Nf3 as line 21

5…a6: Black wants to hold the pawn with b5.
6.O-O: You castle calmly. If Black plays b5, you answer with Ne5 and a4 and attack the pawn chain.
6…Nc6: Black develops and keeps the pawn.
7.e3: You secure d4 and prepare Qe2 and Qxc4. The knight on c6 now bites on granite.
7…Bd7: Black prepares b5.
8.Qe2: The queen attacks c4. If Black holds it with b5, b3 breaks the chain.
8…b5: Black holds the pawn – but the pawns on a6, b5 and c4 become targets.
9.Rd1: The rook supports d4 and prepares e4. Stockfish prefers b3 at once against the chain.
9…Be7: A little passive (Stockfish wanted Bb4).
10.b3: Stockfish's move: you break the chain. After cxb3 axb3 the a-file opens for your rook, and Black's queenside pawns become weak.
10…cxb3: From here Stockfish plays on alone (depth 30) – the games go no further.
11.axb3: You recapture with the a-pawn – the a-file opens against a6.
11…O-O: Black castles and brings the king to safety before playing c5 or e5.
12.Nc3: The knight attacks the pawn on b5.
12…Bd6: The bishop goes to d6 and eyes h2.
13.Bb2: The bishop goes to b2 onto the long diagonal and covers d4.
13…h6: Black takes g5 from your bishop and gives his king air.
14.e4: 14.e4 – you take the centre.
14…e5: 14...e5 attacks the centre – level. Stockfish: level (+0.09).
15.Nxb5: With 15.Nxb5 you take on b5 and open the queenside. Stockfish sees you slightly ahead (+0.14).

Line 23: 3…d5 4.Bg2 dxc4 5.Nf3 a6 6.O-O Nc6 7.e3 Bd7 8.Qe2 b5 9.Rd1 Bd6 10.e4 Bb4 11.b3 cxb3 12.axb3 O-O 13.Bb2 h6 14.Nc3 Re8 15.Nh4

up to 9.Rd1 as line 22

9…Bd6: The bishop leaves the e-file – but now e4 comes closer.
10.e4: You take the centre and threaten e5, forking the bishop on d6 and the knight on f6.
10…Bb4: From here Stockfish plays on alone (depth 30) – the games go no further.
11.b3: 11.b3 attacks the pawn on c4 and opens lines.
11…cxb3: Black takes on b3 and opens the a-file.
12.axb3: You recapture with the a-pawn and have the half-open a-file.
12…O-O: Black castles and brings the king to safety before playing c5 or e5.
13.Bb2: The bishop comes to the long diagonal.
13…h6: Black takes g5 from your bishop and gives his king air.
14.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
14…Re8: The rook goes to e8 and supports the freeing move e5.
15.Nh4: With 15.Nh4 the knight aims at f5, and the advance of the f-pawn becomes possible. Stockfish sees you slightly ahead (+0.19).

Line 24: 3…d5 4.Bg2 dxc4 5.Nf3 a6 6.O-O Nc6 7.e3 Bd7 8.Qe2 Bd6 9.Qxc4 O-O 10.b3 Nb4 11.Nc3 Bc6 12.Rd1 Nfd5 13.Nxd5 Bxd5 14.Qe2 f5 15.Ba3

up to 8.Qe2 as line 23

8…Bd6: The bishop goes to d6 and prepares castling.
9.Qxc4: You win back the pawn on c4.
9…O-O: Black castles and brings the king to safety before playing c5 or e5.
10.b3: b3 wins back the pawn on c4 or opens the b-file – White releases the tension on the queenside.
10…Nb4: From here Stockfish plays on alone (depth 30) – the games go no further. The knight jumps to b4 and eyes c2 and d3.
11.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
11…Bc6: The bishop goes to c6 and keeps the long diagonal.
12.Rd1: The rook goes to d1 behind the pawn on d4.
12…Nfd5: The knight jumps to d5 and offers a trade.
13.Nxd5: You trade the knight on d5.
13…Bxd5: Black recaptures with the bishop; it stands strongly on d5.
14.Qe2: The queen goes to e2 and covers c4 and e4.
14…f5: 14...f5 supports the bishop on d5 – level. Stockfish: level (+0.06).
15.Ba3: With 15.Ba3 you attack the knight on b4. Stockfish: level (+0.03).

Line 25: 3…d5 4.Bg2 dxc4 5.Nf3 a6 6.O-O Nc6 7.e3 Rb8 8.Nfd2 e5 9.Bxc6 bxc6 10.dxe5 Ng4 11.Nxc4 Be6 12.Nbd2 Bb4 13.Qc2 h5 14.b3 h4 15.Nf3

up to 7.e3 as line 24

7…Rb8: The rook prepares b5 and leaves the long diagonal.
8.Nfd2: The knight heads for c4 and wins back the pawn. At the same time your bishop's diagonal opens.
8…e5: With 8...e5 Black attacks the centre.
9.Bxc6: 9.Bxc6 – you give the bishop on g2 for the knight and spoil Black's pawns.
9…bxc6: Black recaptures with the b-pawn and has doubled pawns.
10.dxe5: You take the pawn on e5.
10…Ng4: The knight attacks the pawn on e5.
11.Nxc4: The knight takes the pawn on c4 and defends e5.
11…Be6: From here Stockfish plays on alone (depth 30) – the games go no further.
12.Nbd2: The knight goes to d2 and on to b3.
12…Bb4: The bishop pins your knight on d2 and disturbs your development.
13.Qc2: The queen goes to c2 and covers the knight.
13…h5: Black attacks with the h-pawn.
14.b3: b3 wins back the pawn on c4 or opens the b-file – White releases the tension on the queenside.
14…h4: 14...h4 attacks your kingside. Stockfish: level (+0.11).
15.Nf3: With 15.Nf3 you attack the pawn on h4 and cover your king. Stockfish: level (+0.06).

Line 26: 3…d5 4.Bg2 dxc4 5.Nf3 a6 6.O-O b5 7.Ne5 Nd5 8.a4 Bb7 9.b3 c3 10.e4 b4 11.exd5 Bxd5 12.Qh5 g6 13.Qh3 Ra7 14.Nd2 cxd2 15.Bxd2

up to 6.O-O as line 25

6…b5: Inaccurate (Stockfish wanted Nc6): Black holds the pawn, but the rook on a8 stands on the long diagonal.
7.Ne5: The knight opens the diagonal: now the bishop on g2 threatens to take the rook on a8.
7…Nd5: The knight blocks the diagonal.
8.a4: You attack the pawn on b5. If it falls, the whole a6–b5–c4 chain collapses. Stockfish first plays e4 to drive away the knight on d5.
8…Bb7: The bishop reinforces d5.
9.b3: A second lever against the chain. Stockfish prefers axb5 axb5 Rxa8 with e4 – either way you are better.
9…c3: Black pushes the pawn instead of exchanging (Stockfish wanted cxb3).
10.e4: Stockfish's move: you drive away the knight on d5. After b4 exd5 Bxd5 comes Qh5 with an attack on the kingside.
10…b4: From here Stockfish plays on alone (depth 30) – the games go no further.
11.exd5: You take the knight on d5.
11…Bxd5: Black recaptures with the bishop and lines up against your bishop on g2.
12.Qh5: The queen attacks the pawns on f7 and h7.
12…g6: Black drives the queen away.
13.Qh3: The queen goes to h3 and avoids the attack.
13…Ra7: The rook goes to a7 and covers the second rank.
14.Nd2: 14.Nd2 – you give the knight back to get rid of the annoying pawn on c3.
14…cxd2: Black takes the knight on d2 – the position is sharp, you stand slightly better. Stockfish: level (+0.22).
15.Bxd2: After 15.Bxd2 the pawn on c3 is gone and your pieces come into play quickly – Stockfish sees you clearly better (+0.5).

Line 27: 3…d5 4.Bg2 dxc4 5.Nf3 a6 6.O-O b5 7.Ne5 c6 8.b3 cxb3 9.Nxc6 Qb6 10.Na5 Ra7 11.Nxb3 Be7 12.e4 O-O 13.Be3 Qd8 14.h3 h6 15.N1d2

up to 7.Ne5 as line 26

7…c6: Black shields the rook with c6, but it is inaccurate (Stockfish wanted Nd5).
8.b3: Stockfish's move: you attack the chain. After cxb3, Nxc6 crashes in on c6 and attacks the queen on d8 – you are clearly better (+0.74).
8…cxb3: From here Stockfish plays on alone (depth 30) – the games go no further.
9.Nxc6: 9.Nxc6 – the knight takes on c6 and attacks the queen on d8.
9…Qb6: The queen attacks your knight on c6 – the knight is deep in Black's position.
10.Na5: The knight drops back to a5 and attacks the pawn on b3.
10…Ra7: The rook goes to a7 and covers the second rank.
11.Nxb3: You win back the pawn on b3.
11…Be7: The bishop goes to e7 and prepares castling.
12.e4: 12.e4 – you build a strong centre.
12…O-O: Black castles and brings the king to safety before playing c5 or e5.
13.Be3: The bishop goes to e3 and attacks your queen.
13…Qd8: The queen retreats to d8 and covers the kingside.
14.h3: 14.h3 gives your king air and takes g4 from the bishop.
14…h6: Black takes g5 from your bishop – you stand better, you are a pawn up. Stockfish sees you ahead (+0.66).
15.N1d2: With 15.N1d2 you develop the last piece. With the pawns on d4 and e4 you have a big centre – Stockfish sees you clearly ahead (+0.63).

Line 28: 3…d5 4.Bg2 dxc4 5.Nf3 c5 6.O-O Nc6 7.Ne5 Bd7 8.Na3 cxd4 9.Naxc4 Bc5 10.Qb3 O-O 11.Bf4 Qc8 12.Rfd1 Rd8 13.Rac1 Nd5 14.Nxf7 Kxf7 15.Ne5

up to 5.Nf3 as line 27

5…c5: Black attacks your centre at once.
6.O-O: You castle and keep calm. Stockfish then shows Nc6 dxc5 Qxd1 Rxd1 – a quiet endgame with a slight edge for you.
6…Nc6: The knight increases the pressure on d4.
7.Ne5: The knight attacks c6 and unleashes the bishop on g2. Then you win back the pawn with Na3 and Naxc4. Stockfish prefers the quiet dxc5.
7…Bd7: Black guards c6 once more.
8.Na3: The knight heads for c4 and wins back the pawn.
8…cxd4: Black takes in the centre.
9.Naxc4: The pawn is back. Your knights are active, and you will collect the pawn on d4 later.
9…Bc5: The bishop guards d4.
10.Qb3: The queen attacks the pawn on b7 and supports your knights.
10…O-O: Black castles; Stockfish wanted Nd5 here.
11.Bf4: You develop your last bishop with an eye on c7 and b8.
11…Qc8: The queen guards b7 and d7.
12.Rfd1: Stockfish's move: the rook attacks the pawn on d4. You will win back the pawn and stand slightly better.
12…Rd8: From here Stockfish plays on alone (depth 30) – the games go no further.
13.Rac1: The rook goes to the c-file against the bishop on c5.
13…Nd5: The knight attacks the bishop on f4.
14.Nxf7: 14.Nxf7 – you sacrifice the knight on f7!
14…Kxf7: Black takes the knight on f7 with the king – level. Stockfish: level (0).
15.Ne5: With 15.Ne5+ the knight gives check and your pieces go after the king. For the piece you have enough attack – Stockfish: level (0).

Line 29: 3…d5 4.Bg2 dxc4 5.Nf3 c5 6.O-O Nc6 7.Ne5 Bd7 8.Na3 cxd4 9.Naxc4 Nxe5 10.Nxe5 Qb6 11.Nxd7 Nxd7 12.Qa4 Qb4 13.Qxb4 Bxb4 14.Rd1 Bc5 15.Bxb7

up to 9.Naxc4 as line 28

9…Nxe5: Black trades the annoying knight.
10.Nxe5: The knight is back on e5 and attacks d7 and f7.
10…Qb6: The queen attacks b2.
11.Nxd7: Stockfish's move: you take the bishop and get the bishop pair. After Nxd7 Qa4 you win back the pawn on d4.
11…Nxd7: From here Stockfish plays on alone (depth 30) – the games go no further.
12.Qa4: 12.Qa4 pins the knight on d7 against the king.
12…Qb4: Black offers the queen trade.
13.Qxb4: You trade queens and go into the endgame.
13…Bxb4: Black recaptures with the bishop and attacks your queenside.
14.Rd1: The rook attacks the pawn on d4.
14…Bc5: The bishop goes to c5 and attacks d4. Stockfish: level (+0.21).
15.Bxb7: With 15.Bxb7 you take the pawn on b7. Stockfish sees you slightly ahead (+0.25).

Line 30: 3…d5 4.Bg2 dxc4 5.Nf3 c5 6.O-O Nbd7 7.Na3 Nb6 8.Nxc4 Nxc4 9.Qa4 Bd7 10.Qxc4 cxd4 11.Nxd4 Qb6 12.a4 a5 13.Nb5 Bc5 14.Be3 Bxe3 15.Nc7

up to 6.O-O as line 29

6…Nbd7: A mistake (Stockfish wanted Nc6): the knight is passive on d7. With Na3 you win back c4 and are clearly better (+0.6).
7.Na3: The knight aims at c4. Stockfish rates Nbd2 just as well.
7…Nb6: Black guards c4.
8.Nxc4: You take anyway: after Nxc4 comes Qa4+ and you win the piece back.
8…Nxc4: Black recaptures.
9.Qa4: Check – and at the same time the queen attacks the knight on c4. That is the trick of this line.
9…Bd7: Black blocks the check.
10.Qxc4: Material is level, but you have the stronger bishop and the better centre (+0.58).
10…cxd4: From here Stockfish plays on alone (depth 30) – the games go no further.
11.Nxd4: You recapture with the knight.
11…Qb6: The queen attacks your knight on d4 and eyes b2.
12.a4: 12.a4 gains space and prepares the square b5 for the knight.
12…a5: 12...a5 fixes your pawn on a4 and secures b4.
13.Nb5: The knight jumps to b5 and aims at c7 and d6.
13…Bc5: The bishop goes to c5 and attacks f2.
14.Be3: You offer the bishop trade.
14…Bxe3: Black trades on e3 – you stand slightly better. Stockfish sees you ahead (+0.34).
15.Nc7: With 15.Nc7+ the knight gives check and attacks the rook on a8. Stockfish sees you slightly ahead (+0.28).

Line 31: 3…d5 4.Bg2 dxc4 5.Nf3 Bd7 6.Ne5 Bc6 7.Nxc6 Nxc6 8.e3 Qd7 9.O-O Rb8 10.Qe2 b5 11.b3 cxb3 12.axb3 Rb6 13.Nc3 a6 14.Bb2 Bb4 15.Na2

up to 5.Nf3 as line 30

5…Bd7: The bishop wants to go to c6 to oppose your bishop on g2.
6.Ne5: The knight attacks the bishop on d7 and the pawn on c4 and opens the diagonal.
6…Bc6: Black offers the bishop trade.
7.Nxc6: You take the bishop and keep your bishop pair.
7…Nxc6: The knight is now active on c6.
8.e3: You guard d4 against the knight on c6 and prepare Qe2 and Qxc4.
8…Qd7: Black wants to castle long or press on d4 with Rd8.
9.O-O: The king goes to safety. Stockfish shows Nd2 against c4 as an alternative.
9…Rb8: A mistake (Stockfish wanted Rd8): the rook leaves the centre. After Qe2 you win back c4 and are clearly better (+0.6).
10.Qe2: The queen attacks c4. Stockfish shows Bd6 Qxc4 e5 Nc3 and then d5 – you gain space in the centre.
10…b5: Black holds the pawn on c4.
11.b3: Stockfish's move: you break the chain. After cxb3 axb3 you open the a-file and attack the knight on c6 with Bb2 and the bishop on g2.
11…cxb3: From here Stockfish plays on alone (depth 30) – the games go no further.
12.axb3: The a-file opens.
12…Rb6: The rook goes to b6 and covers the third rank.
13.Nc3: The knight attacks the pawn on b5.
13…a6: 13...a6 supports the pawn on b5 and holds the queenside.
14.Bb2: The bishop goes to b2 – you stand slightly better. Stockfish sees you ahead (+0.43).
14…Bb4: Black pins the knight on c3.
15.Na2: With 15.Na2 you attack the bishop on b4. Stockfish sees you slightly ahead (+0.36).

Line 32: 3…d5 4.Bg2 dxc4 5.Nf3 Bb4 6.Bd2 a5 7.Qc2 Bxd2 8.Qxd2 c6 9.a4 b5 10.axb5 cxb5 11.Qg5 O-O 12.Qxb5 Ba6 13.Qxa5 Bb7 14.Qxd8 Rxa1 15.Qxf8

up to 5.Nf3 as line 31

5…Bb4: 5...Bb4+ – Black gives check.
6.Bd2: You interpose the bishop.
6…a5: Black supports the bishop on b4.
7.Qc2: 7.Qc2 attacks the pawn on c4.
7…Bxd2: Black trades the dark bishops and simplifies.
8.Qxd2: The queen recaptures and covers d4 – she stands actively.
8…c6: From here Stockfish plays on alone (depth 30) – the games go no further.
9.a4: 9.a4 – you attack Black's pawn chain.
9…b5: 9...b5 supports the extra pawn on c4.
10.axb5: You take on b5 and open the a-file.
10…cxb5: Black recaptures with the c-pawn and keeps b5.
11.Qg5: The queen attacks the knight on f6 and the pawn on g7.
11…O-O: Black castles and brings the king to safety before playing c5 or e5.
12.Qxb5: You take the pawn on b5.
12…Ba6: The bishop goes to a6 and covers the pawn on b5 against your queen.
13.Qxa5: You also take the pawn on a5 – now comes a sequence of trades.
13…Bb7: The bishop goes to b7 and attacks f3.
14.Qxd8: 14.Qxd8 – you trade queens, and Black takes the rook on a1.
14…Rxa1: Black takes the rook on a1 – level. Stockfish: level (+0.05).
15.Qxf8: With 15.Qxf8+ you take the rook on f8 with check. After the trades Stockfish sees the position as level (+0.04).

Line 33: 3…d5 4.Bg2 dxc4 5.Nf3 Bb4 6.Bd2 Be7 7.Qa4 Bd7 8.Qxc4 Bc6 9.O-O Nbd7 10.Nc3 Ne4 11.Qd3 Nxc3 12.bxc3 O-O 13.Rfe1 f5 14.a4 Rc8 15.Red1

up to 6.Bd2 as line 32

6…Be7: Black drops the bishop back.
7.Qa4: 7.Qa4+ – check, and then the queen collects the pawn on c4.
7…Bd7: The bishop attacks your queen on a4 and gains a tempo.
8.Qxc4: You win back the pawn on c4.
8…Bc6: The bishop lines up against your bishop on g2.
9.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
9…Nbd7: From here Stockfish plays on alone (depth 30) – the games go no further.
10.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
10…Ne4: The knight attacks the knight on c3.
11.Qd3: The queen goes to d3 and attacks the knight on e4.
11…Nxc3: Black trades on c3 and simplifies – every piece less reduces your pressure.
12.bxc3: You recapture with the pawn and strengthen the centre.
12…O-O: Black castles and brings the king to safety before playing c5 or e5.
13.Rfe1: The rook goes to e1 and prepares e4.
13…f5: Black secures the square e4 with 13...f5.
14.a4: 14.a4 gains space on the queenside and threatens a5.
14…Rc8: The rook goes to c8 – you stand slightly better. Stockfish: level (+0.26).
15.Red1: With 15.Red1 you put the rook behind the pawn on d4 – the advance e2–e4 remains your plan. Stockfish sees you slightly ahead (+0.38).

Line 34: 3…d5 4.Bg2 dxc4 5.Nf3 Nbd7 6.O-O Rb8 7.a4 a6 8.a5 Bd6 9.Qc2 O-O 10.Rd1 b5 11.axb6 Bb7 12.bxc7 Qxc7 13.Nc3 Nd5 14.e4 Nb4 15.Qe2

up to 5.Nf3 as line 33

5…Nbd7: Inaccurate (Stockfish wanted Nc6): the knight is passive and does not guard c4. You stand comfortably (+0.49).
6.O-O: You castle and calmly win back c4 later, for example with Nfd2 or the queen.
6…Rb8: Black wants to play b5 to hold c4.
7.a4: You stop b5. Now Black can hardly hold c4.
7…a6: From here Stockfish plays on alone (depth 30) – the games go no further.
8.a5: 8.a5 – you fix Black's queenside.
8…Bd6: The bishop goes to d6 and prepares castling.
9.Qc2: The queen attacks the pawn on c4.
9…O-O: Black castles and brings the king to safety before playing c5 or e5.
10.Rd1: The rook goes to d1 and supports the pawn on d4.
10…b5: With 10...b5 Black tries to hold the pawn on c4.
11.axb6: You take en passant.
11…Bb7: The bishop goes to b7 onto the long diagonal.
12.bxc7: You also take the pawn on c7.
12…Qxc7: Black recaptures with the queen; she stands on the c-file against your queen.
13.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
13…Nd5: The knight jumps to d5 and attacks the knight on c3.
14.e4: 14.e4 – you build the centre and drive the knight away.
14…Nb4: The knight attacks your queen on c2 – you stand slightly better. Stockfish sees you ahead (+0.32).
15.Qe2: With 15.Qe2 you attack the pawn on c4. Stockfish sees you slightly ahead (+0.36).

Line 35: 3…d5 4.Bg2 dxc4 5.Nf3 Nbd7 6.O-O c5

up to 6.O-O as line 34

6…c5: Transposition: the position is the same as after c5 O-O Nbd7 – it goes on there with Na3. (transposition)

Line 36: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Bb7 10.Rd1 Nbd7 11.Nc3 dxc4 12.Nd2 Nd5 13.Nxc4 Nxf4 14.gxf4 Qc7 15.e3 Rac8 16.Rac1

up to 4.Bg2 as line 35

4…Bb4: An in-between check: Black wants to lure your bishop to d2, where it is less active, and then retreat with Be7.
5.Bd2: You block with the bishop. If the black bishop retreats, you later bring yours to f4.
5…Be7: The bishop goes back – Black thinks your bishop is worse on d2 than on c1.
6.Nf3: Normal development; castling short comes next.
6…O-O: Black castles.
7.O-O: You castle too. You guard the pawn on c4 with Qc2 when needed.
7…c6: Black supports d5.
8.Qc2: The queen guards c4 and makes room for Bf4 – now your bishop gets a better diagonal.
8…b6: Black prepares Bb7 or Ba6.
9.Bf4: The bishop finds the h2–b8 diagonal and aims at c7 and b8. So the detour via d2 has cost you hardly any time.
9…Bb7: The bishop takes its place behind the c6–d5 chain.
10.Rd1: The rook takes the d-file for opening the centre later. Stockfish then shows Ne5 as the plan.
10…Nbd7: Black completes development.
11.Nc3: The last knight joins the game and supports e4. Stockfish expects dxc4, after which Nd2 wins back the pawn.
11…dxc4: Black takes the pawn and wants to trade your bishop on f4 with Nd5.
12.Nd2: The knight goes to win back the pawn on c4 and opens your bishop's diagonal at the same time.
12…Nd5: The knight attacks your bishop on f4.
13.Nxc4: You win back the pawn. You let the bishop on f4 be exchanged.
13…Nxf4: Black gets the bishop pair.
14.gxf4: You recapture with the g-pawn. The structure looks unusual, but the pawn on f4 controls e5, and the g-file is half-open.
14…Qc7: The queen attacks the pawn on f4.
15.e3: You guard f4 and secure the centre. The position is level; 82 % of these games ended in a draw.
15…Rac8: The rook prepares c5.
16.Rac1: Stockfish's move: your rook goes to the c-file too. The position is level (0.00).

Line 37: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Bb7 10.Rd1 Nbd7 11.Nc3 dxc4 12.Nd2 Nd5 13.Nxc4 Nxf4 14.gxf4 Qc7 15.e3 Rad8 16.a4

up to 15.e3 as line 36

15…Rad8: Black puts the rook on the d-file.
16.a4: With 16.a4 you gain space on the queenside. Stockfish: level (0).

Line 38: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Bb7 10.Rd1 Nbd7 11.Nc3 dxc4 12.Nd2 Nd5 13.Nxc4 Nxf4 14.gxf4 Nf6 15.e3

up to 14.gxf4 as line 37

14…Nf6: Black brings the knight to f6.
15.e3: With 15.e3 you strengthen the pawn on d4. Stockfish: level (+0.04).

Line 39: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Bb7 10.Rd1 Nbd7 11.Nc3 Rc8 12.Ne5 Nh5 13.Bc1 Qc7 14.Nxd7 Qxd7 15.e4

up to 11.Nc3 as line 38

11…Rc8: A mistake (Stockfish wanted dxc4): Black gives you time for Ne5. In Stockfish's line you jump to e5, Black has to bring the knight back via h5 to f6, and with e4 you take over the centre and are clearly better (+0.61).
12.Ne5: The knight jumps into the centre, unleashes the bishop on g2 and attacks the knight on d7.
12…Nh5: The knight attacks your bishop on f4.
13.Bc1: Stockfish's move: the bishop calmly retreats. Now the knight on h5 stands on the rim, and after g6 you play e4 (+0.72).
13…Qc7: From here Stockfish plays on alone (depth 30) – the games go no further.
14.Nxd7: You trade the knight on d7.
14…Qxd7: The queen recaptures on d7 – you stand better. Stockfish sees you ahead (+0.73).
15.e4: With 15.e4 you take the centre, and the knight on h5 is on the rim. Stockfish sees you clearly ahead (+0.66).

Line 40: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Bb7 10.Rd1 Nbd7 11.Nc3 Nh5 12.Bc1 f5 13.Bd2 Rc8 14.Rac1 h6 15.Qa4

up to 11.Nc3 as line 39

11…Nh5: Black chases your bishop on f4.
12.Bc1: The bishop retreats. The knight on h5 is on the rim and will soon have to go back.
12…f5: Inaccurate (Stockfish wanted Nhf6): Black builds a Stonewall, but the square e5 becomes weak (+0.5).
13.Bd2: Stockfish's move: the bishop goes back to d2 and connects the rooks. Stockfish plans Rac1 and cxd5.
13…Rc8: From here Stockfish plays on alone (depth 30) – the games go no further.
14.Rac1: The rook goes to c1 onto the c-file – that is where things will be decided.
14…h6: Black gives the king air – you stand slightly better. Stockfish sees you ahead (+0.45).
15.Qa4: With 15.Qa4 the queen attacks the pawn on a7. The knight on h5 is on the rim, and after 12...f5 the square e5 is weak – Stockfish sees you slightly ahead (+0.48).

Line 41: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Bb7 10.Rd1 Na6 11.a3 Rc8 12.Ne5 dxc4 13.Qxc4 Nd5 14.Nc3 Bd6 15.Qa4

up to 10.Rd1 as line 40

10…Na6: Inaccurate (Stockfish wanted Nbd7): the knight stands on the rim. After a3 it has no good square (+0.54).
11.a3: Stockfish's move: you take the square b4 away from the knight.
11…Rc8: From here Stockfish plays on alone (depth 30) – the games go no further.
12.Ne5: The knight goes into the centre and opens the diagonal of your bishop on g2 against b7.
12…dxc4: Black takes on c4 and opens the diagonal.
13.Qxc4: The queen recaptures and attacks the knight on a6.
13…Nd5: The knight jumps to d5 and attacks the bishop on f4.
14.Nc3: You attack the knight on d5.
14…Bd6: The bishop goes to d6 and attacks the knight on e5 – you stand slightly better. Stockfish sees you ahead (+0.33).
15.Qa4: With 15.Qa4 you attack the knight on a6. Stockfish sees you slightly ahead (+0.15).

Line 42: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Ba6 10.Nbd2 Nbd7 11.Rfe1 Nh5 12.Be5 Rc8 13.cxd5 cxd5 14.Qa4 Bb7 15.Qxa7

up to 9.Bf4 as line 41

9…Ba6: The bishop attacks c4.
10.Nbd2: The knight guards c4. Stockfish prefers cxd5 with Nc3.
10…Nbd7: Black finishes development.
11.Rfe1: Stockfish's move: the rook supports the break e4.
11…Nh5: From here Stockfish plays on alone (depth 30) – the games go no further. Black attacks the bishop on f4.
12.Be5: The bishop steps into the centre.
12…Rc8: The rook goes to c8 onto the c-file and sets itself against your queen or rook.
13.cxd5: You trade on d5 and open the c-file.
13…cxd5: Black recaptures with the c-pawn – the structure is symmetrical, the c-file open.
14.Qa4: The queen attacks the bishop on a6.
14…Bb7: The bishop goes back to b7 – level. Stockfish: level (0).
15.Qxa7: With 15.Qxa7 you take the pawn on a7. In return Black gets play on the c-file – Stockfish: level (0).

Line 43: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Nbd7 10.Rd1 Bb7

up to 9.Bf4 as line 42

9…Nbd7: Black develops the knight first.
10.Rd1: The rook goes to the d-file. After Bb7 you are back in the main line.
10…Bb7: Transposition to the main line with Bb7 Rd1 Nbd7 – it goes on there with Nc3. (transposition)

Line 44: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Nbd7 10.Rd1 Ba6 11.Ne5 Rc8 12.Nc3 Bxc4 13.Nxc4 dxc4 14.e4 b5 15.a4

up to 10.Rd1 as line 43

10…Ba6: The bishop attacks c4.
11.Ne5: Stockfish's move: the knight jumps into the centre and unleashes the bishop on g2 against c6.
11…Rc8: The rook goes to c8 and prepares c5.
12.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
12…Bxc4: From here Stockfish plays on alone (depth 30) – the games go no further. Black takes on c4.
13.Nxc4: You recapture with the knight; it stands actively on c4.
13…dxc4: Black takes back the knight on c4 – level. Stockfish: level (0).
14.e4: 14.e4 – you build a big centre.
14…b5: Black holds the pawn on c4.
15.a4: With 15.a4 you attack the pawn on b5. Stockfish: level (0).

Line 45: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 b6 9.Bf4 Nbd7 10.Rd1 Ba6 11.Ne5 Nxe5 12.dxe5 Nd7 13.cxd5 cxd5 14.e4 Rc8 15.Nc3

up to 11.Ne5 as line 44

11…Nxe5: Black trades your strong knight on e5.
12.dxe5: The pawn on e5 takes space from Black.
12…Nd7: From here Stockfish plays on alone (depth 30) – the games go no further.
13.cxd5: You trade on d5 and open the c-file.
13…cxd5: Black recaptures with the c-pawn – the structure is symmetrical, the c-file open.
14.e4: 14.e4 – you attack the centre.
14…Rc8: The rook goes to c8 and attacks your queen – you stand slightly better. Stockfish: level (+0.18).
15.Nc3: With 15.Nc3 you develop the last knight and attack d5. Stockfish sees you slightly ahead (+0.28).

Line 46: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 Nbd7 9.Bf4 b6

up to 8.Qc2 as line 45

8…Nbd7: Black develops the knight before b6.
9.Bf4: The bishop goes to the h2–b8 diagonal, as planned.
9…b6: Transposition: this is the same position as after b6 Bf4 Nbd7 – it goes on there with Rd1. (transposition)

Line 47: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 Nbd7 9.Bf4 Nh5 10.Bc1 Nhf6

up to 9.Bf4 as line 46

9…Nh5: Black chases your bishop at once (Stockfish wanted b6).
10.Bc1: Calmly back: the knight on h5 is on the rim and will soon have to return to f6.
10…Nhf6: Transposition: this is the closed-system position with c6, Qc2 and Nbd7 – it goes on there with b3. (transposition)

Line 48: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 Nbd7 9.Bf4 Nh5 10.Bc1 f5 11.b3 a5 12.Nc3 Nhf6 13.Ng5 Nb8 14.Bb2 Bd6 15.Nf3

up to 10.Bc1 as line 47

10…f5: Inaccurate (Stockfish wanted Nhf6): Black builds a Stonewall, but the square e5 becomes weak (+0.47).
11.b3: You free b2 or a3 for the bishop to activate it. Stockfish prefers Nbd2 with Ne5.
11…a5: From here Stockfish plays on alone (depth 30) – the games go no further.
12.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
12…Nhf6: The knight returns to f6 and covers e4.
13.Ng5: The knight attacks the pawn on e6.
13…Nb8: The knight retreats to b8 and wants to reach c6.
14.Bb2: The bishop goes to b2 onto the long diagonal and covers d4.
14…Bd6: The bishop goes to d6 – you stand slightly better. Stockfish sees you ahead (+0.48).
15.Nf3: With 15.Nf3 the knight comes back, and the square e5 remains your target. Stockfish sees you slightly ahead (+0.44).

Line 49: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 Nbd7 9.Bf4 Ne4 10.Nc3 g5 11.Bc1 f5 12.Be3 Rf7 13.Rad1 a5 14.Na4 Bf6 15.c5

up to 9.Bf4 as line 48

9…Ne4: Inaccurate (Stockfish wanted b6): the knight is active but can be exchanged (+0.33).
10.Nc3: You challenge the knight on e4 with your own knight.
10…g5: Black attacks the bishop on f4 and risks a lot on the kingside.
11.Bc1: The bishop retreats to c1 and avoids g4.
11…f5: From here Stockfish plays on alone (depth 30) – the games go no further.
12.Be3: The bishop goes to e3 and eyes a7.
12…Rf7: The rook goes to f7 and covers the second rank.
13.Rad1: The rook goes to d1 behind the pawn on d4.
13…a5: 13...a5 gains space on the queenside and threatens a4.
14.Na4: The knight goes to a4 and controls c5 and b6.
14…Bf6: The bishop goes to f6 – you stand slightly better. Stockfish sees you ahead (+0.30).
15.c5: With 15.c5 you gain space on the queenside. Black's kingside is weakened – Stockfish sees you slightly ahead (+0.31).

Line 50: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O c6 8.Qc2 Nbd7 9.Bf4 a5 10.Rd1 a4 11.h4 h6 12.a3 b5 13.c5 Ne4 14.Nc3 f5 15.Nxe4

up to 9.Bf4 as line 49

9…a5: Black gains space on the queenside.
10.Rd1: Stockfish's move: the rook goes to the d-file, and Ne5 brings pressure in the centre.
10…a4: From here Stockfish plays on alone (depth 30) – the games go no further.
11.h4: 11.h4 – you gain space on the kingside.
11…h6: Black takes g5 from your bishop and gives his king air.
12.a3: You stop the pawn on a4.
12…b5: 12...b5 gains space and attacks c4.
13.c5: You close the queenside.
13…Ne4: The knight jumps to e4 – a strong square.
14.Nc3: The knight attacks the knight on e4 and wants to trade it.
14…f5: 14...f5 supports the knight on e4 – level. Stockfish: level (0).
15.Nxe4: With 15.Nxe4 you trade the strong knight on e4. Stockfish: level (0).

Line 51: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O Nbd7 8.Qc2 c6

up to 7.O-O as line 50

7…Nbd7: Black develops the knight.
8.Qc2: The queen guards c4. After c6 you are back in the main line.
8…c6: Transposition: the position is the same as after c6 Qc2 Nbd7 – it goes on there with Bf4. (transposition)

Line 52: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 O-O 7.O-O Nbd7 8.Qc2 Ne4 9.h4 c6 10.Bf4 f5 11.Nc3 Qe8 12.Rac1 h6 13.e3 Bf6 14.Ne2 g5 15.Bc7

up to 8.Qc2 as line 51

8…Ne4: The knight jumps to e4 and attacks your bishop on d2.
9.h4: With 9.h4 you secure the square g5 and gain space.
9…c6: From here Stockfish plays on alone (depth 30) – the games go no further.
10.Bf4: The bishop takes an active post on f4.
10…f5: 10...f5 supports the knight on e4 – the Stonewall.
11.Nc3: You attack the knight on e4.
11…Qe8: The queen goes to e8 and on to h5.
12.Rac1: The rook goes to c1 onto the c-file – that is where things will be decided.
12…h6: Black takes g5 from your bishop and gives his king air.
13.e3: 13.e3 supports d4 and closes the diagonal of the bishop on f6.
13…Bf6: The bishop goes to f6 and eyes d4.
14.Ne2: The knight goes to e2 and on to f4 – you stand slightly better. Stockfish sees you ahead (+0.37).
14…g5: Black attacks the bishop on f4.
15.Bc7: With 15.Bc7 the bishop steps aside and stays active. Black's kingside is weakened by 14...g5 – Stockfish sees you slightly ahead (+0.49).

Line 53: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 c6 7.Qc2 O-O 8.O-O

up to 6.Nf3 as line 52

6…c6: Black supports d5 before castling.
7.Qc2: The queen guards c4 and keeps e4 under control.
7…O-O: Black castles.
8.O-O: Transposition: after you castle it is the same position as after O-O O-O c6 Qc2 – it goes on there with Bf4. (transposition)

Line 54: 3…d5 4.Bg2 Bb4 5.Bd2 Be7 6.Nf3 c6 7.Qc2 b6 8.O-O O-O

up to 7.Qc2 as line 53

7…b6: Black delays castling.
8.O-O: Stockfish's move: you castle and wait for Black to castle. After that e4 is your aim.
8…O-O: From here Stockfish plays on alone (depth 30) – the games go no further. 8...O-O – By transposition the game goes on in a line the course already teaches. (transposition)

Line 55: 3…d5 4.Bg2 Bb4 5.Bd2 Bd6 6.Nf3 c6 7.Nc3 O-O 8.Qc2 Nbd7 9.b3 e5 10.cxd5 cxd5 11.dxe5 Nxe5 12.O-O Nxf3 13.Bxf3 Be6 14.Qd3 Rc8 15.Rad1

up to 5.Bd2 as line 54

5…Bd6: Black drops the bishop back to d6.
6.Nf3: You develop the knight.
6…c6: 6...c6 supports d5 and closes the long diagonal of your bishop on g2.
7.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
7…O-O: From here Stockfish plays on alone (depth 30) – the games go no further.
8.Qc2: The queen supports the advance e2–e4.
8…Nbd7: The knight goes to d7 and prepares e5.
9.b3: b3 wins back the pawn on c4 or opens the b-file – White releases the tension on the queenside.
9…e5: Black frees the position with 9...e5.
10.cxd5: You trade on d5 and fix the pawn structure.
10…cxd5: Black recaptures with the c-pawn – the structure is symmetrical, the c-file open.
11.dxe5: You take on e5 and attack the bishop on d6 and the knight on f6.
11…Nxe5: Black recaptures with the knight and attacks f3.
12.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
12…Nxf3: Black trades on f3 and simplifies – every piece less reduces your pressure.
13.Bxf3: You recapture with the bishop – now it presses on d5.
13…Be6: The bishop goes to e6 and covers the isolated pawn on d5.
14.Qd3: The queen goes to d3 and attacks the isolated pawn on d5.
14…Rc8: The rook goes to c8 onto the c-file and sets itself against your queen or rook.
15.Rad1: With 15.Rad1 you put the rook against the isolated pawn on d5. Stockfish: level (−0.01).

Line 56: 3…d5 4.Bg2 Bb4 5.Bd2 Bd6 6.Nf3 O-O 7.O-O c6 8.Nc3 Be7 9.b3 Ne4 10.Rc1 Ba3 11.Rc2 Nxd2 12.Qxd2 Na6 13.Nb1 Be7 14.Rcc1 Bd7 15.Qb2

up to 6.Nf3 as line 55

6…O-O: Black castles and brings the king to safety before playing c5 or e5.
7.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
7…c6: From here Stockfish plays on alone (depth 30) – the games go no further.
8.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
8…Be7: The bishop goes back to e7.
9.b3: b3 wins back the pawn on c4 or opens the b-file – White releases the tension on the queenside.
9…Ne4: The knight attacks the knight on c3 and the bishop on d2.
10.Rc1: The rook goes to c1 onto the c-file – that is where things will be decided.
10…Ba3: Black attacks the rook on c1.
11.Rc2: The rook goes to c2 and avoids the bishop on a3.
11…Nxd2: Black trades your bishop on d2.
12.Qxd2: The queen recaptures and connects the rooks.
12…Na6: The knight goes to a6 and on to c7.
13.Nb1: The knight attacks the bishop on a3.
13…Be7: The bishop retreats to e7 and covers the kingside.
14.Rcc1: With 15.Qb2 you put the queen on the long diagonal. Stockfish sees you slightly ahead (+0.15).
14…Bd7: The bishop goes to d7 and connects the rooks.
15.Qb2: The queen goes to b2 onto the long diagonal – level.

Line 57: 3…d5 4.Bg2 c6 5.Nf3 Nbd7 6.Qc2 Bd6 7.O-O O-O 8.Nbd2 Re8 9.Rd1 Qe7 10.Re1 e5 11.e4 dxe4 12.Nxe4 Nxe4 13.Qxe4 Qf8 14.Qc2 Bb4 15.Ng5

up to 4.Bg2 as line 56

4…c6: Black supports d5 with a solid triangle – similar to the Slav Defense.
5.Nf3: Normal development; castling follows soon.
5…Nbd7: Black prepares e5 or b6.
6.Qc2: The queen guards c4 and controls e4 – so Black can hardly play dxc4.
6…Bd6: The bishop is more active than on e7 and supports e5.
7.O-O: The king goes to safety. You are well prepared for e5.
7…O-O: Both sides have castled.
8.Nbd2: The knight guards c4 and e4. Stockfish prefers Rd1; the result is similar.
8…Re8: Black prepares e5.
9.Rd1: The rook takes the d-file – if Black opens up with e5, it is in the right place at once.
9…Qe7: The queen supports e5.
10.Re1: Stockfish's move: the rook moves to the e-file, where the fight is now. After e5 you play e4 yourself.
10…e5: From here Stockfish plays on alone (depth 30) – the games go no further. Black frees the position with 10...e5.
11.e4: 11.e4 – you open the centre.
11…dxe4: Black takes on e4 and opens the centre.
12.Nxe4: You recapture with the knight; it stands centrally.
12…Nxe4: Black trades on e4 and simplifies – every piece less reduces your pressure.
13.Qxe4: The queen stands in the centre on e4.
13…Qf8: The queen goes to f8 and covers the kingside.
14.Qc2: The queen retreats to c2 – level. Stockfish: level (+0.11).
14…Bb4: Black attacks the rook on e1.
15.Ng5: With 15.Ng5 the knight attacks the pawns on f7 and h7. Stockfish: level (+0.05).

Line 58: 3…d5 4.Bg2 c6 5.Nf3 Nbd7 6.Qc2 Be7 7.O-O O-O

up to 6.Qc2 as line 57

6…Be7: The quieter bishop move.
7.O-O: Castling short. After O-O you are in the closed system.
7…O-O: Transposition: this is the closed-system position with c6, Qc2 and Nbd7 – it goes on there with b3. (transposition)

Line 59: 3…d5 4.Bg2 c6 5.Nf3 Be7 6.O-O O-O

up to 5.Nf3 as line 58

5…Be7: Black develops the bishop and will castle soon.
6.O-O: You castle – the position usually leads to the closed system.
6…O-O: Transposition to the closed system after Be7 Nf3 O-O O-O c6 – it goes on there with Qc2. (transposition)

Line 60: 3…d5 4.Bg2 c6 5.Nf3 Be7 6.O-O Nbd7 7.Qc2

up to 6.O-O as line 59

6…Nbd7: Black delays castling.
7.Qc2: The queen guards c4. This transposes to Nbd7 Qc2 Be7 O-O. (transposition)

Line 61: 3…d5 4.Bg2 c6 5.Nf3 Bd6 6.O-O O-O 7.Qc2 Nbd7

up to 5.Nf3 as line 60

5…Bd6: The bishop aims at your kingside and supports e5.
6.O-O: You castle and then play Qc2, Nbd2 and Rd1 as in the other lines.
6…O-O: From here Stockfish plays on alone (depth 30) – the games go no further.
7.Qc2: The queen goes to c2 and covers c4 and e4 – she prepares e4. Stockfish: level (+0.20).
7…Nbd7: By transposition the game goes on in a line the course already teaches. (transposition)

Line 62: 3…d5 4.Bg2 c6 5.Nf3 dxc4 6.Ne5 Bb4 7.Bd2 Be7 8.e3 b5 9.Nxc6 Nxc6 10.Bxc6 Bd7 11.Bxa8 Qxa8 12.f3 e5 13.O-O e4 14.fxe4 Bg4 15.Qc2

up to 5.Nf3 as line 61

5…dxc4: Inaccurate (Stockfish wanted Be7): Black takes after all and wants to keep the pawn with b5.
6.Ne5: The knight attacks c4 and eyes c6. Stockfish rates the position at +0.22 afterwards.
6…Bb4: Black develops the bishop with check.
7.Bd2: Stockfish's move: you block the check. In Stockfish's line Be7 e3 b5 Nxc6 your knight crashes in on c6.
7…Be7: From here Stockfish plays on alone (depth 30) – the games go no further.
8.e3: 8.e3 prepares to win back the pawn on c4.
8…b5: Black holds the pawn on c4 with 8...b5.
9.Nxc6: 9.Nxc6 – you take the pawn on c6!
9…Nxc6: Black takes the knight on c6 – now your bishop on g2 comes into play.
10.Bxc6: The bishop takes the knight and attacks the rook on a8.
10…Bd7: The bishop goes to d7 and attacks the bishop on c6.
11.Bxa8: You win the exchange.
11…Qxa8: Black recaptures, and the black queen stands on the long diagonal.
12.f3: 12.f3 closes the long diagonal in front of your king.
12…e5: 12...e5 attacks the centre and opens the bishop.
13.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
13…e4: 13...e4 attacks the pawn on f3 and weakens your king.
14.fxe4: You take on e4 – you stand slightly better. Stockfish: level (+0.11).
14…Bg4: Black attacks the queen on d1.
15.Qc2: With 15.Qc2 the queen steps aside. You have the exchange, Black has pressure and pawns – Stockfish: level (0).

Line 63: 3…d5 4.Bg2 c6 5.Nf3 Bb4 6.Nbd2 dxc4 7.a3 Bxd2 8.Bxd2 b5 9.b3 cxb3 10.Qxb3 O-O 11.Rc1 Bb7 12.O-O Nbd7 13.Bb4 Re8 14.Ne5 Rc8 15.Rfd1

up to 5.Nf3 as line 62

5…Bb4: A check Stockfish does not like (it wanted Be7).
6.Nbd2: Stockfish's move: the knight blocks the check and also guards c4. You stand comfortably (+0.44).
6…dxc4: From here Stockfish plays on alone (depth 30) – the games go no further. Black takes the pawn on c4.
7.a3: 7.a3 questions the bishop on b4.
7…Bxd2: Black trades on d2 and gives you the bishop pair.
8.Bxd2: You recapture with the bishop and have the bishop pair.
8…b5: Black holds the pawn on c4.
9.b3: You attack the pawn chain at once.
9…cxb3: Black takes on b3 and opens the lines.
10.Qxb3: You win the pawn back, and the queen presses on b5.
10…O-O: Black castles and brings the king to safety before playing c5 or e5.
11.Rc1: The rook goes to the c-file.
11…Bb7: The bishop goes to b7 onto the long diagonal against your bishop on g2.
12.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
12…Nbd7: The knight goes to d7 and supports the freeing moves c5 and e5.
13.Bb4: The bishop attacks the rook on f8.
13…Re8: The rook goes to e8 and prepares e5.
14.Ne5: The knight jumps to e5 and attacks c6 and d7.
14…Rc8: The rook goes to c8 – you stand slightly better. Stockfish: level (+0.15).
15.Rfd1: With 15.Rfd1 your rooks stand on c1 and d1. Stockfish sees you slightly ahead (+0.23).

Chapter 2: 3…Bb4

Line 64: 3…Bb4 4.Bd2 Be7 5.Bg2 d5

3…Bb4: The bishop check (17 % of games): Black holds back d5 for now and stays flexible.
4.Bd2: You block with the bishop and ask Black whether he wants to trade. Then Bg2 follows as always.
4…Be7: The bishop goes back; usually d5 follows with a transposition.
5.Bg2: The bishop comes to the long diagonal.
5…d5: Transposition: this is the position after d5 Bg2 Bb4+ Bd2 Be7 – it goes on there with Nf3. (transposition)

Line 65: 3…Bb4 4.Bd2 Qe7 5.Bg2 Nc6 6.e3 e5 7.d5 Bxd2 8.Qxd2 Nb8 9.Nc3 d6 10.Nh3 e4 11.Nf4 h6 12.Qd4 Bf5 13.g4 c5 14.dxc6 Nxc6 15.Qd2

up to 4.Bd2 as line 64

4…Qe7: The queen guards the bishop on b4 and prepares Nc6 and e5.
5.Bg2: The bishop goes to g2. Stockfish prefers Nf3, but you are fine either way.
5…Nc6: The knight attacks d4 and supports e5.
6.e3: You give d4 solid cover. The knight from g1 later goes to e2, so your bishop on g2 stays free.
6…e5: Black attacks the centre.
7.d5: You push past and gain space. The knight on c6 has to move.
7…Bxd2: Black first trades the bishops.
8.Qxd2: Back with the queen. Stockfish prefers Nxd2 – both moves keep the balance.
8…Nb8: The knight goes back and wants to return via a6 or d7.
9.Nc3: Development with an eye on e4 and b5. Stockfish prefers d6 with a queen trade.
9…d6: Black closes the centre.
10.Nh3: Stockfish's move: the knight heads via h3 to f2, so you can firm up the centre with f3 and e4. Stockfish sees Black slightly ahead here (−0.11) – a calm, closed position.
10…e4: From here Stockfish plays on alone (depth 30) – the games go no further. Black gains space with 10...e4.
11.Nf4: The knight comes into play via f4.
11…h6: Black takes g5 from your knight.
12.Qd4: The queen attacks the pawn on e4.
12…Bf5: The bishop goes to f5 and covers the pawn on e4.
13.g4: 13.g4 attacks the bishop on f5.
13…c5: Black attacks your pawn on d5.
14.dxc6: You take en passant.
14…Nxc6: Black recaptures with the knight – level. Stockfish: level (+0.04).
15.Qd2: With 15.Qd2 the queen drops back. Stockfish: level (+0.09).

Line 66: 3…Bb4 4.Bd2 Qe7 5.Bg2 Nc6 6.e3 e5 7.d5 Nb8 8.Nc3 a5 9.Nge2 d6 10.e4 O-O 11.a3 Bc5 12.h3 c6 13.O-O h6 14.Qc2 cxd5 15.exd5

up to 7.d5 as line 65

7…Nb8: Inaccurate (Stockfish wanted Bxd2+): now you can choose how to recapture, and you are better (+0.42).
8.Nc3: Stockfish's move: you develop the knight. Stockfish plans Nge2 and castling (+0.52).
8…a5: From here Stockfish plays on alone (depth 30) – the games go no further.
9.Nge2: The knight goes to e2 and on to c3 or g3.
9…d6: 9...d6 supports the pawn on e5.
10.e4: 10.e4 – you build a big centre.
10…O-O: Black castles and brings the king to safety before playing c5 or e5.
11.a3: You attack the bishop on b4.
11…Bc5: The bishop goes to c5 and eyes f2.
12.h3: 12.h3 takes g4 from the bishop.
12…c6: 12...c6 attacks your pawn on d5 and opens the c-file.
13.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
13…h6: Black takes g5 from your bishop and gives his king air.
14.Qc2: The queen goes to c2 and covers the c-file.
14…cxd5: Black takes on d5 – you stand slightly better. Stockfish sees you ahead (+0.38).
15.exd5: With 15.exd5 you recapture with the e-pawn – your pawn on d5 takes space from Black. Stockfish sees you slightly ahead (+0.38).

Line 67: 3…Bb4 4.Bd2 Qe7 5.Bg2 Nc6 6.e3 Bxd2 7.Qxd2 d5 8.Ne2 dxc4 9.Na3 e5 10.O-O exd4 11.exd4 O-O 12.Nxc4 Be6 13.Ne5 Bd5 14.Bxd5 Nxd5 15.Nxc6

up to 6.e3 as line 66

6…Bxd2: Black trades the bishops.
7.Qxd2: Stockfish's move: the queen recaptures, and the knight from g1 goes to e2 later.
7…d5: From here Stockfish plays on alone (depth 30) – the games go no further.
8.Ne2: The knight goes to e2 and covers d4 and c3.
8…dxc4: Black takes the pawn on c4 – the typical gambit pawn in the Catalan.
9.Na3: The knight wants to win back the pawn on c4.
9…e5: Black attacks the centre.
10.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
10…exd4: Black trades on d4 and opens the e-file.
11.exd4: You recapture and now have an isolated pawn on d4, but active pieces.
11…O-O: Black castles and brings the king to safety before playing c5 or e5.
12.Nxc4: You win back the pawn on c4.
12…Be6: The bishop attacks your knight on c4.
13.Ne5: The knight jumps to e5 and attacks the knight on c6.
13…Bd5: The bishop offers a trade against your bishop on g2.
14.Bxd5: You trade on d5 and simplify.
14…Nxd5: Black recaptures with the knight – level.
15.Nxc6: With 15.Nxc6 you trade the knight on c6. Stockfish: level (+0.09).

Line 68: 3…Bb4 4.Bd2 Qe7 5.Bg2 Nc6 6.e3 O-O 7.Ne2 Bxd2 8.Qxd2 d5 9.cxd5 exd5 10.Nbc3 Qd8 11.f3 Ne7 12.Rd1 Nd7 13.O-O Nb6 14.Nf4 c6 15.Nd3

up to 6.e3 as line 67

6…O-O: Inaccurate (Stockfish wanted Bxd2+): Black castles, but you get a smoother development (+0.48).
7.Ne2: The knight comes to e2 so the bishop on g2 stays free. After Bxd2+ you recapture with the knight.
7…Bxd2: From here Stockfish plays on alone (depth 30) – the games go no further.
8.Qxd2: The queen recaptures on d2 and covers d4.
8…d5: 8...d5 builds a centre against your bishop on g2.
9.cxd5: 9.cxd5 – you exchange in the centre.
9…exd5: Black recaptures with the pawn and keeps d5.
10.Nbc3: The knight attacks the pawn on d5.
10…Qd8: The queen goes back to d8 and covers d5.
11.f3: 11.f3 prepares the advance e3–e4.
11…Ne7: The knight goes to e7 and on to f5.
12.Rd1: The rook goes to d1 against the pawn on d5.
12…Nd7: The knight goes to d7 and supports the freeing moves c5 and e5.
13.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
13…Nb6: The knight goes to b6 and covers d5.
14.Nf4: The knight attacks the pawn on d5.
14…c6: 14...c6 supports d5 – you stand slightly better. Stockfish sees you ahead (+0.42).
15.Nd3: With 15.Nd3 the knight aims at c5 and e5. Your plan remains the advance of the e-pawn – Stockfish sees you slightly ahead (+0.31).

Line 69: 3…Bb4 4.Bd2 Qe7 5.Bg2 O-O 6.Nc3 d5 7.Nf3 dxc4 8.Ne5 Rd8 9.a3 Bxc3 10.bxc3 Nbd7 11.Nxc4 Nb6 12.Ne5 Nfd7 13.Nf3 h6 14.Bc1 e5 15.a4

up to 5.Bg2 as line 68

5…O-O: Black castles first.
6.Nc3: Development with pressure on d5 and e4. Stockfish prefers Nf3 – after Nc3 the position becomes more level.
6…d5: From here Stockfish plays on alone (depth 30) – the games go no further.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development.
7…dxc4: Black takes the pawn on c4 – you will soon win it back.
8.Ne5: The knight goes to e5 and wants to win back the pawn on c4.
8…Rd8: The rook goes to d8 against the pawn on d4.
9.a3: You attack the bishop on b4.
9…Bxc3: Black trades on c3 and gives you doubled pawns.
10.bxc3: You get the bishop pair.
10…Nbd7: The knight goes to d7 and attacks the knight on e5.
11.Nxc4: You win the pawn back.
11…Nb6: The knight goes to b6 and attacks the knight on c4.
12.Ne5: The knight jumps to e5 and avoids the trade.
12…Nfd7: The knight attacks the knight on e5 again.
13.Nf3: The knight returns to f3 and covers d4.
13…h6: Black takes g5 from your bishop and gives his king air.
14.Bc1: The bishop goes to c1 and on to a3.
14…e5: 14...e5 attacks the centre – level.
15.a4: With 15.a4 you gain space and threaten to drive away the knight on b6 with the a-pawn. You have the bishop pair – Stockfish: level (0).

Line 70: 3…Bb4 4.Bd2 Qe7 5.Bg2 Bxd2 6.Qxd2 d5 7.Nf3 O-O 8.O-O Nbd7 9.Qf4 Qb4 10.Qxc7 Ne8 11.Qf4 Qxc4 12.Nc3 Qc7 13.Ne5 Qb6 14.Nd3 Qc7 15.Qf3

up to 5.Bg2 as line 69

5…Bxd2: Black trades at once.
6.Qxd2: Stockfish's move: the queen recaptures. Nf3, castling and later Ne5 follow.
6…d5: From here Stockfish plays on alone (depth 30) – the games go no further.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development.
7…O-O: Black castles and brings the king to safety before playing c5 or e5.
8.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
8…Nbd7: The knight goes to d7 and supports the freeing moves c5 and e5.
9.Qf4: 9.Qf4 – the queen attacks the pawn on c7.
9…Qb4: Black attacks the pawns on c4 and b2.
10.Qxc7: You take the pawn on c7.
10…Ne8: The knight goes to e8 and covers the pawn on c7.
11.Qf4: The queen returns to f4 and eyes c7.
11…Qxc4: Black wins the pawn back.
12.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
12…Qc7: The queen goes to c7 and offers a queen trade.
13.Ne5: The knight jumps to e5 and attacks d7.
13…Qb6: The queen goes to b6 and attacks b2.
14.Nd3: The knight goes to d3 and covers b2.
14…Qc7: The queen goes to c7 – you stand slightly better. Stockfish sees you ahead (+0.31).
15.Qf3: With 15.Qf3 the queen stands actively and presses on d5. Stockfish sees you slightly ahead (+0.31).

Line 71: 3…Bb4 4.Bd2 Bxd2 5.Qxd2 d5 6.Bg2 c6 7.Nf3 Nbd7 8.O-O O-O 9.Rc1 b6 10.Ne5 Bb7 11.Nc3 Qe7 12.cxd5 exd5 13.Nd3 Ne4 14.Qd1 Rfd8 15.e3

up to 4.Bd2 as line 70

4…Bxd2: Black trades bishops at once.
5.Qxd2: The queen recaptures and controls the dark squares.
5…d5: Black builds the classic centre.
6.Bg2: The bishop comes to the long diagonal and presses on d5.
6…c6: 6...c6 supports d5 and closes the long diagonal of your bishop on g2.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development.
7…Nbd7: The knight goes to d7 and supports the freeing moves c5 and e5.
8.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
8…O-O: Black castles and brings the king to safety before playing c5 or e5.
9.Rc1: The rook goes to the c-file.
9…b6: 9...b6 prepares the bishop on b7 on the long diagonal.
10.Ne5: The knight goes to e5 and opens the diagonal of the bishop on g2.
10…Bb7: From here Stockfish plays on alone (depth 30) – the games go no further.
11.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
11…Qe7: The queen goes to e7 and connects the rooks.
12.cxd5: 12.cxd5 – you exchange in the centre and open the c-file.
12…exd5: Black recaptures with the pawn and keeps d5.
13.Nd3: The knight goes to d3 and eyes c5, e5 and f4.
13…Ne4: Black attacks the queen on d2.
14.Qd1: The queen retreats to d1 and avoids the knight on e4.
14…Rfd8: The rook goes to d8 and covers d5 – level.
15.e3: With 15.e3 you reinforce the pawn on d4. The position is quiet – Stockfish: level (+0.06).

Line 72: 3…Bb4 4.Bd2 Bxd2 5.Qxd2 d5 6.Bg2 Nbd7 7.Nf3 c6

up to 6.Bg2 as line 71

6…Nbd7: The knight goes to d7 and supports the freeing moves c5 and e5.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development. Stockfish: level (+0.14).
7…c6: By transposition the game goes on in a line the course already teaches. (transposition)

Line 73: 3…Bb4 4.Bd2 Bxd2 5.Qxd2 d5 6.Bg2 O-O 7.Nf3 c6 8.O-O Nbd7

up to 6.Bg2 as line 72

6…O-O: Black castles and brings the king to safety before playing c5 or e5.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development.
7…c6: 7...c6 supports d5 and closes the long diagonal of your bishop on g2.
8.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal. Stockfish: level (+0.15).
8…Nbd7: By transposition the game goes on in a line the course already teaches. (transposition)

Line 74: 3…Bb4 4.Bd2 Bxd2 5.Qxd2 O-O 6.Nf3 d5 7.Bg2

up to 5.Qxd2 as line 73

5…O-O: Black castles.
6.Nf3: Stockfish's move: normal development, then Bg2 and castling.
6…d5: From here Stockfish plays on alone (depth 30) – the games go no further.
7.Bg2: By transposition the game goes on in a line the course already teaches. (transposition)

Line 75: 3…Bb4 4.Bd2 Bxd2 5.Qxd2 d6 6.Bg2 Nc6 7.Nf3 a6 8.Nc3 O-O 9.O-O Rb8 10.b3 b5 11.d5 Ne7 12.dxe6 fxe6 13.cxb5 axb5 14.a4 bxa4 15.bxa4

up to 5.Qxd2 as line 74

5…d6: Inaccurate (Stockfish wanted O-O): Black is a little passive (+0.44).
6.Bg2: The bishop goes to g2. Nc3 and Nf3 follow – you have more space.
6…Nc6: From here Stockfish plays on alone (depth 30) – the games go no further.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development.
7…a6: Black prepares the advance b7–b5.
8.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
8…O-O: Black castles and brings the king to safety before playing c5 or e5.
9.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
9…Rb8: The rook goes to b8 and prepares b5.
10.b3: b3 wins back the pawn on c4 or opens the b-file – White releases the tension on the queenside.
10…b5: 10...b5 opens the queenside against your pawn on c4.
11.d5: 11.d5 – you attack the knight on c6 and gain space.
11…Ne7: The knight goes to e7 and covers d5.
12.dxe6: You trade on e6 – afterwards Black's pawn on e6 is a weakness.
12…fxe6: Black recaptures with the f-pawn and opens the f-file.
13.cxb5: You take on b5 and open the a-file.
13…axb5: Black recaptures with the a-pawn.
14.a4: 14.a4 attacks the pawn on b5.
14…bxa4: Black takes on a4 – you stand slightly better. Stockfish sees you ahead (+0.31).
15.bxa4: With 15.bxa4 you recapture. Black's pawns on e6 and d6 can become targets – Stockfish sees you slightly ahead (+0.36).

Line 76: 3…Bb4 4.Bd2 c5 5.Bxb4 cxb4 6.Bg2 O-O 7.e4 d6 8.Ne2 e5 9.O-O Bg4 10.a3 Qb6 11.axb4 Qxb4 12.f3 Bd7 13.Qc1 Rc8 14.Na3 Nc6 15.Qc3

up to 4.Bd2 as line 75

4…c5: Inaccurate (Stockfish wanted Be7): Black invites the trade and attacks d4.
5.Bxb4: You trade. Afterwards a black pawn stands on b4, far advanced and hard to protect.
5…cxb4: The pawn on b4 takes the square c3 from your knight.
6.Bg2: The bishop goes to g2 – the centre belongs to you, because Black no longer has a c-pawn.
6…O-O: Black castles.
7.e4: You build a big centre with d4 and e4. Stockfish prefers the calmer e3 with Ne2.
7…d6: Black prepares e5.
8.Ne2: The knight goes to e2 because c3 is controlled by the pawn on b4.
8…e5: Black challenges the centre.
9.O-O: You castle. Stockfish prefers a3 to attack the pawn on b4 at once – the position is level.
9…Bg4: From here Stockfish plays on alone (depth 30) – the games go no further. Black attacks the knight on e2.
10.a3: 10.a3 attacks the pawn on b4.
10…Qb6: The queen goes to b6 and attacks b2 and d4.
11.axb4: You take on b4 and open the a-file.
11…Qxb4: Black wins the pawn back and attacks c4.
12.f3: 12.f3 attacks the bishop on g4.
12…Bd7: The bishop retreats to d7.
13.Qc1: The queen goes to c1 and covers c4.
13…Rc8: The rook goes to c8 against the pawn on c4.
14.Na3: The knight defends the pawn on c4.
14…Nc6: The knight comes to c6 – level. Stockfish: level (-0.03).
15.Qc3: With 15.Qc3 you offer the queen trade. Stockfish: level (0).

Line 77: 3…Bb4 4.Bd2 a5 5.Bg2 d6 6.Nc3 O-O 7.Nf3 Re8 8.Qc2 e5 9.dxe5 dxe5 10.Rd1 Qe7 11.O-O h6 12.a3 Bxc3 13.Bxc3 Nc6 14.Rfe1 a4 15.Nd2

up to 4.Bd2 as line 76

4…a5: Black secures the bishop on b4 with the a-pawn.
5.Bg2: The bishop comes to the long diagonal.
5…d6: Inaccurate (Stockfish wanted d5): Black sets up a passive position (+0.34).
6.Nc3: The knight controls e4 and d5. Stockfish prefers Nf3 and castling.
6…O-O: From here Stockfish plays on alone (depth 30) – the games go no further.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development.
7…Re8: The rook goes to e8 and supports e5.
8.Qc2: The queen goes to c2 and covers c4 and e4 – she prepares e4.
8…e5: Black frees the position with 8...e5.
9.dxe5: You take on e5 and open the d-file.
9…dxe5: Black recaptures with the pawn.
10.Rd1: The rook takes the open d-file.
10…Qe7: The queen goes to e7 and covers e5.
11.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
11…h6: Black takes g5 from your bishop and gives his king air.
12.a3: You attack the bishop on b4.
12…Bxc3: Black trades on c3 and gives you the bishop pair.
13.Bxc3: You have the bishop pair.
13…Nc6: The knight comes to c6 and covers e5.
14.Rfe1: The rook goes to e1 and supports e4.
14…a4: 14...a4 gains space on the queenside – level.
15.Nd2: With 15.Nd2 the knight wants to come into play via e4. Stockfish: level (0).

Line 78: 3…Bb4 4.Bd2 a5 5.Bg2 O-O 6.Nf3 b6 7.O-O Bb7 8.Bf4 Be7 9.Nc3 Ne4 10.Qc2 Nxc3 11.bxc3 h6 12.e4 d6 13.Be3 Nd7 14.Nd2 a4 15.f4

up to 5.Bg2 as line 77

5…O-O: Black castles first.
6.Nf3: Stockfish's move: normal development, then Qc2 and castling.
6…b6: Black prepares to develop the bishop to b7.
7.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
7…Bb7: From here Stockfish plays on alone (depth 30) – the games go no further.
8.Bf4: The bishop stands actively on f4.
8…Be7: The bishop goes to e7 and covers the kingside.
9.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
9…Ne4: The knight jumps to e4 and offers a trade.
10.Qc2: The queen goes to c2 and covers c4 and e4 – she prepares e4.
10…Nxc3: Black trades on c3 and gives you doubled pawns.
11.bxc3: You recapture with the pawn and strengthen the centre.
11…h6: Black takes g5 from your bishop and gives his king air.
12.e4: 12.e4 – you build a big centre.
12…d6: 12...d6 keeps e5 under control.
13.Be3: The bishop goes to e3 and covers d4.
13…Nd7: The knight goes to d7 and on to f6.
14.Nd2: The knight goes to d2 and covers e4.
14…a4: 14...a4 gains space – you stand slightly better.
15.f4: With 15.f4 you gain space on the kingside. With the pawns on c4, e4 and f4 you have a lot of space – Stockfish sees you slightly ahead (+0.24).

Line 79: 3…Bb4 4.Bd2 a5 5.Bg2 d5 6.a3 Be7 7.Nf3 c6 8.Qc2 Nbd7 9.Bf4 O-O 10.O-O b6 11.cxd5 cxd5 12.Rc1 Ba6 13.Nc3 h6 14.a4 Nh5 15.Be5

up to 5.Bg2 as line 78

5…d5: Black builds the classic centre.
6.a3: You question the bishop on b4. Stockfish prefers calm development with Nf3 and Qc2 – after a3 the position is level (0.00).
6…Be7: From here Stockfish plays on alone (depth 30) – the games go no further.
7.Nf3: The knight goes to f3 and covers d4 and e5 – the most natural development.
7…c6: 7...c6 supports d5 and closes the long diagonal of your bishop on g2.
8.Qc2: The queen goes to c2 and covers c4 and e4 – she prepares e4.
8…Nbd7: The knight goes to d7 and supports the freeing moves c5 and e5.
9.Bf4: The bishop stands actively on f4.
9…O-O: Black castles and brings the king to safety before playing c5 or e5.
10.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
10…b6: 10...b6 prepares the bishop on a6 or b7.
11.cxd5: 11.cxd5 – you exchange in the centre and open the c-file.
11…cxd5: Black recaptures with the c-pawn – the structure is symmetrical, the c-file open.
12.Rc1: The rook goes to c1 onto the c-file – that is where things will be decided.
12…Ba6: The bishop goes to a6 and eyes e2.
13.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
13…h6: Black takes g5 from your bishop and gives his king air.
14.a4: 14.a4 gains space on the queenside – level.
14…Nh5: Black attacks the bishop on f4.
15.Be5: With 15.Be5 the bishop steps into the centre. Stockfish: level (0).

Chapter 3: 3…c5

Line 80: 3…c5 4.Nf3 cxd4 5.Nxd4 d5 6.Bg2 e5 7.Nf3 d4 8.O-O Nc6 9.e3 Be7 10.exd4 exd4 11.Bf4 O-O 12.Ne5 Qb6 13.Qb3 Na5 14.Qxb6 axb6 15.Nd2

3…c5: 3...c5 – Black attacks the centre at once. Stockfish then sees you slightly ahead (+0.32).
4.Nf3: 4.Nf3 – you develop the knight and hold d4.
4…cxd4: Black trades on d4 and opens the centre.
5.Nxd4: You recapture with the knight, which stands in the centre on d4.
5…d5: Black strikes in the centre at once.
6.Bg2: The bishop presses on d5.
6…e5: Black attacks the knight on d4.
7.Nf3: The knight returns to f3 and attacks e5.
7…d4: Black advances the pawn to d4 and gains space.
8.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
8…Nc6: The knight comes to c6 and covers d4.
9.e3: 9.e3 – you attack the advanced pawn on d4.
9…Be7: The bishop goes to e7 and prepares castling.
10.exd4: You take on d4 and open the e-file.
10…exd4: After the exchange Black's pawn on d4 is isolated – a target for your pieces.
11.Bf4: The bishop develops actively.
11…O-O: Black castles and brings the king to safety before playing c5 or e5.
12.Ne5: The knight goes to e5 and attacks the knight on c6.
12…Qb6: The queen goes to b6 and attacks b2.
13.Qb3: You offer the queen trade.
13…Na5: The knight attacks your queen on b3.
14.Qxb6: You trade queens – level.
14…axb6: From here Stockfish plays on alone (depth 30) – the games go no further.
15.Nd2: With 15.Nd2 you bring the last knight into play. Black's pawn on d4 remains a target – Stockfish: almost level (−0.1).

Line 81: 3…c5 4.Nf3 cxd4 5.Nxd4 d5 6.Bg2 e5 7.Nf3 d4 8.O-O Nc6 9.e3 Be7 10.exd4 exd4 11.Bf4 O-O 12.Ne5 Nxe5 13.Bxe5 Bc5 14.Nd2 Ng4 15.Bf4

up to 12.Ne5 as line 80

12…Nxe5: 12...Nxe5 – Black trades the knight on e5.
13.Bxe5: The bishop stands strongly on e5 and attacks the pawn on d4.
13…Bc5: The bishop goes to c5 and covers d4.
14.Nd2: The knight goes to d2 and on to b3.
14…Ng4: 14...Ng4 attacks the bishop on e5 – but afterwards you get the advantage.
15.Bf4: With 15.Bf4 the bishop steps aside. The pawn on d4 is weak, and your bishop on g2 eyes b7 – Stockfish sees you clearly better (+0.63).

Line 82: 3…c5 4.Nf3 cxd4 5.Nxd4 d5 6.Bg2 e5 7.Nf3 d4 8.O-O Nc6 9.e3 Be7 10.exd4 exd4 11.Bf4 Be6 12.Ne5 Rc8 13.Nd2 Nxe5 14.Bxe5 Ng4 15.Re1

up to 11.Bf4 as line 81

11…Be6: 11...Be6 – Black develops the bishop and attacks the pawn on c4.
12.Ne5: The knight jumps to e5 and attacks c6.
12…Rc8: The rook goes to c8 onto the c-file.
13.Nd2: The knight goes to d2 and on to b3.
13…Nxe5: From here Stockfish plays on alone (depth 30) – the games go no further.
14.Bxe5: You recapture with the bishop – level.
14…Ng4: Black attacks the bishop on e5.
15.Re1: With 15.Re1 you defend the bishop on e5 and put the rook on the open e-file. Stockfish: level (+0.03).

Line 83: 3…c5 4.Nf3 cxd4 5.Nxd4 d5 6.Bg2 e5 7.Nf3 d4 8.O-O Nc6 9.e3 Bc5 10.exd4 exd4 11.Re1 Be6 12.Ng5 O-O 13.Nxe6 fxe6 14.Nd2 Qb6 15.Nb3

up to 9.e3 as line 82

9…Bc5: 9...Bc5 – the bishop supports the pawn on d4.
10.exd4: You take on d4 and attack the bishop on c5.
10…exd4: Black recaptures with the pawn.
11.Re1: The rook takes the open e-file.
11…Be6: The bishop goes to e6 and covers d5.
12.Ng5: The knight attacks the bishop on e6.
12…O-O: Black castles and brings the king to safety before playing c5 or e5.
13.Nxe6: You trade the bishop on e6.
13…fxe6: Black recaptures with the f-pawn and opens the f-file.
14.Nd2: The knight goes to d2 and on to e4.
14…Qb6: The queen goes to b6 – you stand slightly better. Stockfish sees you ahead (+0.44).
15.Nb3: With 15.Nb3 you attack the bishop on c5. The pawn on e6 and the isolated pawn on d4 are weaknesses – Stockfish sees you clearly better (+0.54).

Line 84: 3…c5 4.Nf3 cxd4 5.Nxd4 d5 6.Bg2 e5 7.Nf3 d4 8.O-O Nc6 9.e3 d3 10.Nc3

up to 9.e3 as line 83

9…d3: 9...d3 – the pawn storms forward, but it can hardly be held.
10.Nc3: With 10.Nc3 you develop the knight, and the pawn on d3 will soon fall. Stockfish sees you clearly ahead (+1.06).

Line 85: 3…c5 4.Nf3 cxd4 5.Nxd4 Qc7 6.Nc3 a6 7.Bg2 Qxc4 8.O-O Nc6 9.Nb3 d5 10.Bf4 Be7 11.Rc1 Qb4 12.Re1 O-O 13.e4 Nxe4 14.Bxe4 dxe4 15.Bc7

up to 5.Nxd4 as line 84

5…Qc7: 4...Qc7 – the queen attacks the pawn on c4.
6.Nc3: The knight goes to c3 and supports e4 – your plan in the Catalan.
6…a6: Black takes the square b5 from the knight.
7.Bg2: The bishop goes to g2 onto the long diagonal.
7…Qxc4: Black takes the pawn on c4 – in return you get a big lead in development.
8.O-O: You castle – the bishop on g2 shields your king and presses on the long diagonal.
8…Nc6: The knight comes to c6 and attacks the knight on d4.
9.Nb3: The knight goes to b3 and avoids the trade.
9…d5: 9...d5 builds a centre.
10.Bf4: The bishop develops, eyeing c7 and b8.
10…Be7: From here Stockfish plays on alone (depth 30) – the games go no further.
11.Rc1: The rook goes to the c-file, behind the knight on c3.
11…Qb4: The queen goes to b4 and attacks the bishop on f4 and the knight on c3.
12.Re1: The rook goes to e1 and prepares e4.
12…O-O: Black castles and brings the king to safety before playing c5 or e5.
13.e4: 13.e4 – you open the centre.
13…Nxe4: Black takes on e4 and simplifies.
14.Bxe4: You recapture with the bishop.
14…dxe4: Black recaptures – level.
15.Bc7: With 15.Bc7 the bishop takes an active post inside Black's camp. Stockfish: level (0).