# Chess Opening Theory/1. d4/1...Nf6/2. c4/2...e5/3. dxe5/3...Ng4/4. Bf4/4...Nc6/5. Nf3/5...Bb4/6. Nbd2/6...Qe7/7. a3/7...Ngxe5/8. Nxe5/8...Nxe5/9. e3/9...Bxd2/10. Qxd2/10...d6

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.Bf4 Nc6 5.Nf3 Bb4+ 6.Nbd2 Qe7 7.a3 Ngxe5 8.Nxe5 Nxe5 9.e3 Bxd2+ 10.Qxd2 d6
After 10...d6! White can try (and has tried) about any move that goes into the direction of the aforementioned plan. In particular White has to chose if he wants to start active operations on the queenside immediately (e.g. Rc1, Qc3, c5), or if he wants to finish his development first (with Be2 and 0-0).
The immediate 11.c5!? is a possible pawn sacrifice in order to open some diagonals for the bishops. As Lalic points out, "after 11...dxc5 Black's knight on e5 has lost its support and therefore all tactical motifs based on Qd5 and Bb5+ must be carefully checked". White gets a powerful attack for his pawn but nothing decisive, for example 11...dxc5 12.Qd5 Nc6! 13.Bb5 0-0 14.Bxc6 bxc6 15.Qxc6 Rb8 with a fully viable game according to an analysis from Tseitlin. Another retreat for the knight also occurred, with 11...dxc5 12.Qd5 Ng6 13.Bb5+ Bd7 14.Qxb7 0-0 15.Bxd7 Nxf4.
The same idea can be tried with the preparatory 11.Rc1, and after 11...0-0 12.c5!? dxc5 13.Qd5 Ng6 14.Bg3 White should be reminded that he has not finished his development with 14...Qf6! and a counterattack on b2. Playing Black, Svidler chose a different path with 11...b6 but his opponent Lesiège nevertheless sacrified the pawn with 12.c5!, when play continued 12...bxc5 13.b4 0-0 14.bxc5 Bb7 15.f3 and Svilder destroyed his own pawn structure with 15...dxc5!? in order to activate his pieces and make use of the d-file.
The most popular is 11.Be2 as White delays his queenside play until he has achieved castling. It also gives Black more time to organise defence on the queenside, e.g. 11...0-0 12.0-0 b6! 13.Rac1 Bb7 14.Rfd1 a5 15.b4 Nd7 and the game is still balanced.
* In a game Browne tried 11.Be2 b6 12.e4 but it did not bring the expected activity and he lost.
* Koepcke tried 11.Be2 0-0 12.O-O b6 13.b4 Rd8!? 14.Qc3 and then his opponent Yermolinsky uncorked the cold-blooded 14...c5!, a surprising move that creates the disadvantage of a backward pawn in d6, but Lalic considers "Black's activity is sufficient to compensate for the weakness on d6 and in fact it is the white c4-pawn that could prove vulnerable one day."
* Black can also let his opponent realise the push c4–c5 with 11.Be2 0-0 12.0-0 b6 13.b4 Bb7 14.c5 and then seek counter-chances based on the possession of the d-file with 14...dxc5 15.bxc5 Rfd8.
* Black can insert the preventive a7–a5 for the minor reason of delaying White's push b2–b4 and for the major reason of opening the a-file with a5xb4 once the push b2–b4 has been realised. The advantage for Black of opening the a-file is that white rooks cannot in the same time attack along the c-file and contest the a-file to the black rooks. So generally White abandons the a-file to concentrate on the attack along the c-file, and Black can use the a-file for its own purposes. For example a game Lavrov – Kaposztas saw the moves 11.Be2 0-0 12.0-0 a5 13.Rac1 b6 14.Bg3 Bg7 15.Qc3 Rfe8 16.Rfd1 Nd7 17.b4 axb4 18.axb4 Nf6, with a double-edged position.

## Notes

* ↑ Lalic 1998, p.36
* ↑ Lalic 1998, p.36 Grünberg – Tamm, Chess Bundesliga 1987
* ↑ Tseitlin 1992, p.64
* ↑ Lalic 1998, p.37
* ↑ Lalic 1998, p.38 Svidler – Lesiège, Oakham 1992
* ↑ Lalic 1998, p.38
* ↑ Tseitlin 1992, p.130 Browne – Speelman, Taxco Interzonal 1985
* ↑ Lalic 1998, p.39 Koepcke – Yermolinsky, Los Angeles 1991
* ↑ Lalic 1998, p.41 Twardon – E. Pandavos, Nalenczow 1989
* ↑ Lalic 1998, p.42 Lavrov – Kaposztas, Eger open 1993