London System: free opening course

Key ideas

• Play Bf4 before e3, so the dark-squared bishop is not locked in behind the pawns.
• Build the pyramid d4, e3, c3: it blunts Black's counterplay against d4.
• Put the knights on f3 and d2 and the light-squared bishop on d3, aiming at h7.
• Later, Ne5 and a kingside pawn push (h4 or g4) give a direct attack.
• Against an early ...c5 and ...Qb6, answer the attack on b2 actively: Qb3 to offer a queen trade, or Nc3 so that ...Qxb2 runs into Nxd5 or Nb5 hitting c7.
• Watch the d6 square: when Black's bishop sits on d6 and the queen leaves d8, Bxd6 often wins a piece.

The 6 variations in the course

• Main line against ...d5: 1. d4 d5 2. Bf4 Nf6 3. e3 e6 4. Nf3 c5 5. c3 Nc6 6. Nbd2 Bd6 … — Black mirrors with ...d5 and ...e6. White completes the standard setup and keeps an easy, safe position.
• Against the King's Indian setup: 1. d4 Nf6 2. Nf3 g6 3. Bf4 Bg7 4. e3 O-O 5. Be2 d6 6. h3 Nbd7 … — Black fianchettoes with ...g6 and ...Bg7. White keeps the same structure and often plays h3 so the bishop on f4 has a retreat square.
• Against an early ...c5: 1. d4 d5 2. Bf4 c5 3. e3 Nc6 4. Nf3 Nf6 5. Nbd2 cxd4 6. exd4 Bf5 … — Black hits d4 at once with 2...c5. White develops calmly with e3, Nf3 and Nbd2, recaptures exd4, then uses the Qb3 and Nh4 ideas to bother Black's light-squared bishop.
• Against the Queen's Indian setup (...b6): 1. d4 Nf6 2. Bf4 e6 3. e3 b6 4. Nf3 Bb7 5. h3 c5 6. c3 Be7 … — Black fianchettoes the light-squared bishop with ...b6 and ...Bb7 to control e4. White plays h3, c3, Nbd2 and Bd3, then aims for e4 with Qe2.
• Against the Dutch (...f5): 1. d4 f5 2. Bf4 Nf6 3. e3 e6 4. Nf3 b6 5. Bd3 Bb7 6. Nbd2 Be7 … — Against 1...f5 the London bishop still goes to f4 and controls e5, the square Black's Dutch structure weakens. White builds e3, Bd3, Nbd2, h3, castles and prepares a central break with Qe2 and e4, or c4.
• Jobava London (2.Nc3 and Bf4): 1. d4 d5 2. Nc3 Nf6 3. Bf4 c5 4. e3 cxd4 5. exd4 a6 6. Nf3 Nc6 … — An aggressive alternative: White puts the knight on c3 before the London bishop, eyeing Nb5 against c7. Against ...c5 and ...cxd4, White recaptures exd4 and gets a quick, active development.

Traps you will learn (3)

• The loose bishop on d6 — In the main London, Black's bishop on d6 is guarded only by the queen. If the queen leaves d8 to grab b2 with ...Qb6, Bxd6 simply wins a piece.
• Jobava Nb5 fork — In the Jobava London, knight on c3 plus bishop on f4 both aim at c7. If Black plays ...Bf5 and then ignores Nb5, Nxc7+ forks king and rook.
• Poisoned b2 pawn: Nxd5! — Against 2...c5 and 3...Qb6 White can ignore the attack on b2 with 4.Nc3. If Black grabs the pawn, Nxd5 threatens both Nc7+ and Rb1, and Black loses material.

How the opening courses work

Each course teaches an opening in a few main variations. For every move you read why it is played, which other moves are good, and which tempting moves are mistakes and why. Each course also shows the traps of the opening: the ones you can set and the ones to avoid.

After a lesson you play the moves yourself in a drill. The lines you learn go into your review, which brings them back when you are about to forget them (spaced repetition). 30 line courses add many short lines per opening, a few new ones a day, and every named opening, more than 3,800 lines, has a lesson of its own.