1.e4 This move has been efectuated by the President of Romania, Traian Basescu, who mentioned in his characteristic cheerful manner that he had received very clear indications to advance the king's pawn with two squares. Later, reporter Florin Orban from Radio Romania International speculated about the matter about who would the President receive "indications" from.
1...e5 2.Nf3 Nc6 3.Bb5 Nf6 4.0-0 Nxe4 5.d4 Nd6 6.Bxc6 dxc6 7.dxe5 Nf5 8.Qxd8+ Kxd8 By refraining from his beloved Najdorf Sicilian and choosing the rock-solid Berlin variation, Topalov gave the sensation that he aimed to take some preliminary contact with a player whom he had only faced some 15 years ago in a youth event, which also took place in Romania. However, this might be pure speculation, since the Berlin variation occurs with increasing frequency in the FIDE World Champion's games.
9.Nc3 Ne7 10.Ne4 h6 11.Nd4!? [Surprisingly, this active move has never been played before. The knight enjoys only temporary stability in the centre, because after taking the b5-square under control Black will be able to drive it away with ...c5. The outcome of the battle greatly depends on White's possibility of provoking some damage to the enemy position with the help of this knight, before it gets attacked. The more common continuation is 11.h3 Ng6 12.Re1 ; I have found a game where, in spite of a different move order, White managed to obtain an improved version of White's position after 14 moves. However, this was only as a consequence of Black's careless play at some moment. 11.Bf4 Ng6 12.Bg3 Be7?! (Black should have prepared the transfer of the king to the queen side with 12...Bd7! ) 13.Rad1+ Ke8 14.Nd4 Bd7 15.Rfe1 Now, all White's pieces are optimally placed, while the black king feels quite uncomfortable. 15...c5 16.Nb3 b6 17.Nf6+! gxf6 18.exf6 with better chances for White, Dervishi-Zaja, Austria 2003]
11...b6 12.Rd1 [This is a small concession White has to make in order to prevent the enemy king from reaching absolute safety on the queen side. Of course, he would prefer to place his rooks on the central files (d1 and e1), but 12.Bf4 (preparing the same setup as in the aforementioned game) could be met by 12...c5 13.Nb5 Be6 14.Rad1+ Kc8 and Black has little to complain about.]
12...Ke8 13.Bf4 Ng6 14.Bg3 [White could threaten win a pawn and threaten mate in one with 14.Nxc6? just to resign one move later after 14...Bb7 when all his minor pieces would be handing.]
14...Bb7 White's advantage of space and activity look impressive, but this is usually a delusive sensation in the Berlin variation.
15.f4 [Nisipeanu decides to include more forces into the attack. The tempting 15.e6 would have been also double edged, because it would give up the advantage of space and would help Black develop his king. For instance 15...a6 (Threatening ...c5, with simultaneous attack on both knights. If played immediately, 15...c5? would lead to disaster after 16.Nb5 Bxe4 17.Nxc7+ Ke7 18.Rd7+ Kf6 19.Rxf7+ Kg5 20.Nxa8 with some material advantage and, more important, a crushing domination for White.) 16.f3!? (This move was suggested by Topalov immediately after the game. White intends to maintain some stability in the centre.) 16...c5 17.exf7+ Kxf7 18.Nf5 Ke6 19.Ne3 Rc8 (The more radical 19...Bxe4 20.fxe4 c6 is also entirely playable for Black. His king would feel very comfortable under the shelter offered by the enemy e-pawn, while his compact queen side mass of pawns could become dangerous if advanced gradually.) 20.Rd2 Be7 and Black has a comfortable position because of his active pair of bishops and the centralised king.]
15...a6 16.f5!? [White decides to start concrete action, hoping to take advantage of his advance in development. In the press centre, 16.Re1 Rd8 17.Nf5 was considered to be a better alternative, but Nisipeanu indicated that Black can evacuate the dangerous zone with 17...Kd7 when the concentration of white forces on the king side has a rather sterile character.]
16...c5 Once the long diagonal has been opened for the bishop, Black can hope for adequate counterplay.
17.fxg6 cxd4 18.Rxd4 [The only way to maintain the initiative. 18.gxf7+ would have the drawback of allowing the enemy king to be activated with 18...Kxf7 . The position would suddenly become double-edged, for instance 19.e6+!? (An interesting resource, suggested by IM Mircea Pavlov. After 19.Rxd4?! Ke6 Black is definitely not worse in spite of his small material deficit. His king enjoys safe centralisation, while his pair of bishops is more active than White's minor's pieces. As for the e5-pawn, it will most likely be lost after the previsible exchange of all rooks.) 19...Kg6! (19...Kxe6?! looks slightly risky. After 20.Rxd4 the king feels slightly uncomfortable in the absence of the e-pawn. The attempt to win material with 20...c5?! would only weaken Black's sixth rank when after 21.Rd2 Bxe4 22.Re1 White would recuperate the piece maintaining the more active position.) and now, in view of the threat ...Re8, it would be time for White to think about equality with 20.Rxd4 c5 21.Rd2 Bxe4 22.Re2 Bf5 23.e7 when the presence of opposite coloured bishops in a symmetrical position would make a draw the most probable result.]
18...fxg6 With his poor development, Black cannot afford to maintain the tension in this area.
19.e6 [White opens the diagonal for his bishop, putting the whole black queen side under some danger. He would have no winning chances after 19.Rad1 Bxe4 20.Rxe4 Bc5+ 21.Kf1 Rf8+ 22.Ke2 Rd8 either. His central pawn can be easily blocked and does not present any danger even in the case of exchanging all rooks.]
19...Rd8! [Black defends his c7-pawn by indirect means and forces the exchange of one pair of rooks, which reduces White's attacking potential. The other possible way to simplify the position would be 19...Bxe4?! 20.Rxe4 Bc5+ (driving the king further from the centre) 21.Kh1 Bd6 22.Bxd6 cxd6 but after 23.e7 Ra7 24.Rae1 Black would have big problems with the activation of his king's rook. White would most likely find a favourable way to exchange his e-pawn for any Black pawn from the sixth rank in order to obtain a better single-rook endgame.]
20.Rad1 Rxd4 21.Rxd4 Bxe4 Now, this exchange is well timed for reasons that will be highlighted in the next comment.
22.Rxe4 Bc5+ 23.Kf1 [The king has to get out of his castle because after 23.Kh1 Black would win a tempo with 23...Rf8 anyway in view of the weakness of the first rank, not protected by White's other rook any more.]
23...Rf8+ 24.Ke1 [24.Ke2 looks more active, but would hardly chance anything if Black plays in the same way as in the game. Instead of that, 24...Ke7? would be bad because after 25.Bxc7 Rf2+ 26.Kd3 Rxg2 27.b4 the bishop would have to leave his king alone against the concentrated action of White's pieces, for instance 27...Bg1 28.Bd6+! Kd8 29.Rf4 Rf2 and now, apart from the fact that the bishop ending is easily winning for White, the forced sequence 30.Rf8+ Rxf8 31.e7+! queens immediately.]
24...Bd6 25.Bxd6 cxd6 In spite of the mass simplifications, White seems to maintain some initiative.
26.Rc4 [White has no better way to attack the enemy queen side. 26.Rb4 (suggested by IM Vlad Barnaure) can be met by 26...b5 27.a4 (In case of 27.c4?! Rf4 28.b3 d5 White can get the worse position already.) 27...Rf5 and White cannot make any progress.]
26...Rf5! This simple move solves all Black's problems.
27.Rc8+ [White's intended 27.Rc6 can be adequately met by 27...Rc5 with general exchanges and an obvious draw.]
27...Ke7 28.Rc7+ Kxe6 29.Rxg7 Re5+ Remarkably, the black rook is supported by the own pawns along the whole fifth rank. In order to escape from checks, the king has to hide passively behind his pawns, which would hardly look like a winning attempt. I am not sure whether a draw was agreed here or after some more checks, because after Black's 25th move the electronic transmission of the moves was broken. 1/2-1/2