The idea in one sentence
Black holds d5 with ...c6 to keep the light-squared bishop free, then develops it to f5 before ...e6.
♔ White's plans
- Stop ...b5 with a4 after ...dxc4
- Win back c4 and build the centre with e4
- Use the space on the queenside
♚ Black's plans
- Defend d5 with ...c6, keeping the bishop free
- Take on c4 and develop the bishop to f5
- Pin the knight with ...Bb4
Pawn structure. Solid c6-d5 or c6-e6 structures; few weaknesses for Black.
How to learn it
- Read the idea and the plans: every move below serves one of them.
- In the story, ask of each move: what does it do, what does it stop, what does it prepare, why not the other one?
- Drill your side. At the key moves you name the idea first, then play the move.
- Missed moves come back first next time, and in your journal.
The defining moves
- 2...c6 defends d5 without blocking the c8 bishop.
- 4...dxc4 takes the pawn, intending ...b5 to keep it.
- 5.a4 stops ...b5.
- 5...Bf5 develops the bishop before ...e6.
The line follows the moves masters play most (Lichess masters database), each checked by Stockfish 19 at depth 22; where the book move is not Stockfish's first choice, the story says so. Scores are in pawns from White's side: +0.30 is good for White, −0.30 for Black.