1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6
Garry Kasparov cut his teeth on the Berlin Wall in the 2000 World Championship match. He was unable to win a single white game against Vladimir Kramnik's Berlin Defence, which was subsequently nicknamed the Berlin Wall. Subsequently, 3...Nf6 against the Spanish Game also became increasingly popular among other grandmasters, and on the white side analytical efforts were intensified to find a promising set-up against this super-solid defence. 3...Nf6 attacks the white e-pawn, and to get something out of the position, theory traditionally recommends rapid development with 4.0-0. However, the solid move 4.d3 became an equally popular alternative in modern practice, as it avoids the deeply analysed queenless middlegame of the main variation.
After 4.0-0 Black can take the e-pawn with the consistent 4...Nxe4 (although 4...Lc5 is an alternative that Topalov has occasionally played), the main line then continues with 5.d4 Nd6 6.Bxc6 dxc6 7.dxe5 Nf5 8.Qxd8+ Kxd8.
Here, as in the exchange variation, White has the advantage of the better pawn structure. However, their e-pawn is already on e5, which makes an important difference. Their pawn majority on the kingside can be actively used to create a passed pawn and they also have a slight development advantage. On the surface, the disadvantages of the black position are more obvious: the double pawn, the loss of castling rights, the somewhat unfavourable piece coordination (Nf5 hinders Bc8). On the plus side, however, there is the black bishop pair, and the white e-pawn advanced to e5 can also become a motive for counterplay for Black. The Berlin Defence is ideal for players who like to exchange queens early and have patience for long endgames.