Tarrasch Defence: free opening course

Key ideas

• The d5 pawn is isolated, with no pawns beside it. It is weak in an endgame, but it gives your pieces open lines and space.
• Keep pieces on the board and play actively. Trades help White, who wants to win the d5 pawn.
• Good squares for your pieces are e4 for a knight and e6 for the light bishop. A rook belongs on e8.
• Watch for the ...d4 push. It gains space, kicks the c3 knight and turns the weak pawn into a strong one.
• White aims at d5 with a knight on d4, a bishop on g2 and pressure down the d-file. Always count the attackers before you move a defender.

The 6 variations in the course

• Main line: 9.Bg5 cxd4: 1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. Nf3 Nc6 6. g3 Nf6 … — White fianchettoes the bishop on g2 and pins the f6 knight. Black trades on d4, chases the bishop with ...h6 and puts a rook on e8. The bishop goes back to f8, and Black's pieces defend d5 well.
• 9.dxc5 Bxc5: the d4 push: 1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. Nf3 Nc6 6. g3 Nf6 … — White takes on c5 and Black takes back with the bishop. After 10.Bg5 Black pushes ...d4. The isolated pawn becomes a strong pawn that cramps White's knight. Black keeps an active game.
• 9.b3 Ne4: the e4 outpost: 1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. Nf3 Nc6 6. g3 Nf6 … — White prepares a bishop on b2 to press on d4. Black jumps to e4 and puts the bishop on f6. After the trades on d4 Black develops the last bishop with tempo and has an easy game.
• 5.dxc5 d4: Black grabs space: 1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. dxc5 d4 6. Ne4 Nf6 … — White takes the c5 pawn at once. Black does not hurry to win it back and pushes 5...d4 to gain space with tempo. The knight trade on f6 brings the queen out. Black wins the pawn back and has an easy game.
• 4.e3: the quiet line: 1. d4 d5 2. c4 e6 3. Nc3 c5 4. e3 Nf6 5. Nf3 Nc6 6. cxd5 exd5 … — White keeps the c1 bishop at home and plays a calm set-up. After the trades in the centre both sides have an isolated d-pawn. Black develops the bishops to d6 and e6 and puts a rook on the c-file.
• 5.e4: the Marshall Gambit: 1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. e4 dxe4 6. Nxe4 cxd4 … — White strikes with 5.e4 and opens the centre. Black takes the pawn, then trades on d4. A check on b4 and a bishop trade let Black castle quickly. Black keeps an extra pawn on d4.

Traps you will learn (2)

• 5.dxc5 d4 6.Nb5? Qa5+: the lost knight — After 5.dxc5 d4 the c3 knight must move. The jump to b5 looks active, but the knight has no defender there. A queen check on a5 attacks it, and Black wins a whole piece.
• Marshall Gambit: 6...Qxd4?? 7.Qb3 — A warning for Black. After 6.Bc4 the d4 pawn looks free, but grabbing it with the queen is a big mistake. White's queen comes to b3 and attacks f7 and b7, and Black's position falls apart.

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.