The idea in one sentence
White opens the centre at once with d4; after the trades White gains space with e5 and c4, Black gets the bishop pair and open files.
♔ White's plans
- Strike with d4 before Black is ready
- After Nxc6 and e5, chase the knight with c4
- Use the space on the kingside
♚ Black's plans
- Take on d4 and develop fast
- Accept doubled c-pawns for open lines
- Pressure e5 with ...Qe7, ...Nd5 and ...f6 or ...g6
Pawn structure. Open centre; White's e5 wedge against Black's doubled c-pawns and quick piece play.
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.d4 challenges e5 right away instead of preparing it.
- 3...exd4 takes, since there is no good way to hold e5.
- 4.Nxd4 recaptures and centralises the knight.
- 5.Nxc6 trades before Black can trade on d4, and doubles Black's c-pawns.
- 6.e5 gains space and kicks the knight from f6.
- 6...Qe7 attacks e5 and pins it against White's king on e1, so the pawn cannot capture off the e-file.
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.