The idea in one sentence
White locks the centre with e5 and gains space; the whole game turns on Black's pressure against d4, the base of White's pawn chain.
♔ White's plans
- Gain space with e5
- Defend d4 with c3, Nf3 and later Be3 or Bd3
- Attack on the kingside, where the space is
♚ Black's plans
- Hit d4 with ...c5, ...Nc6 and ...Qb6
- Later undermine e5 with ...f6
- Activate the light-squared bishop, the French problem piece
Pawn structure. Pawn chains d4-e5 against d5-e6: attack the chain at its base.
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
- 3.e5 grabs space and takes f6 from Black's knight.
- 3...c5 attacks the base of the chain, d4.
- 4.c3 defends d4 with a pawn.
- 4...Nc6 adds a second attacker on d4.
- 5...Qb6 adds a third attacker on d4 and also hits b2.
- 6.a3 prepares b4, gaining space on the queenside and stopping ...Bb4.
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.