Topalov enters this game with a difficult decision. Should he try to hold for a draw and push for an all-out win with White in the 4th game, or try to risk potentially losing the match here with Black? These are problems that the super-GM from Bulgaria must answer even before the players sit at the board.
1.e4
c5
2.Nf3
d6
3.d4
cxd4
4.Nxd4
Nf6
5.Nc3
a6
6.a4
Kamsky repeats his relatively experimental line from game one. Even though Topalov and his team were probably expecting this, it is very difficult to react in a mere two days. It's possible that they found no tangible improvement after 6... Nc6 7. a5!? so Topalov deviates back to the more usual Najdorf approach.
6...e5
7.Nf3
Be7
8.Bg5
Be6
9.Bxf6
Bxf6
10.Nd5
Nd7
11.Bc4
Rc8
12.b3
Qa5+
This game's novelty. This practically forces White's response, after which it would only make sense to trade queens. A superficial assessment would be to think that 'simplifications lead to draws', when in fact the absence of queens brings many new strategical ideas to the position.
13.Qd2
Qxd2+
14.Nxd2
Bg5
This is a good time to get a strong hold of the position. The structure is very reminiscent of a Sveshnikov Sicilian. To compensate his backwards d6 pawn and weak d5 square, Black has the pair of bishops and a half open c-file. Of course, this isn't something that he can take advantage of immediately since the position is rather closed. But it contains potential! The old masters believed that obtaining the pair of bishops would eventually grant an advantage, because ultimately the position was bound to become open after pawn exchanges. Although chess has evolved greatly, this maxim still holds some value.
15.Kd1!?
This is an interesting move by the American. The king is perfectly safe on d1, and it holds the queenside somewhat. There is really no advantage in sending the king to the kingside, as it would serve no purpose there. The queenside rook will eventually lift through a4 (after a pawn push to a5) and go to b4, where it would be pressuring the b7 pawn. However, White is not the only one who can push rook pawns...
15...h5!
A good strategical move: Black grabs space on the kingside and prepares a potential rooklift there - but it's also important to understand the psychological implications of such a move. Because of the match situation, it is possible that Kamsky wants to play with as little risk as possible. Clearly he holds no advantage, so he does not want to commit himself to any weaknesses if he cannot see an immediate return. It is possible that for this reason he shuns the most natural move 16.h4 and gives Black a decent amount of space in the kingside. In my opinion, unnecessarily.
16.Re1?!
[16.h4
is of course the most natural continuation, but then White has to cope with the fact that h4 will be weak and g5 might be a possible break in the future. All bishop retreats make some sense at this point, but the most natural would seem to be 16...Bd8
eyeing that h4 pawn. 17.g3
Ba5
Kamsky might have looked at this position and not liked it. The computer suggests that terribly inhuman move 18.Rb1, so it's understandable how he didn't go for this line. However, White's position is solid, even if rather planless.]
16...h4
Black quickly grabs the space he was provided. White can hardly allow the pawn to go all the way to h3, so he must stop it now.
17.h3
Nf6
18.Nxf6+
[18.Nb6
was a natural alternative. However after 18...Rc5
19.a5
Nh5
Black begins to build up some pressure on the kingside. Maybe saying that Black is better is not quite true, but it does seem more pleasant to play with the Black pieces.]
18...gxf6!=/+
Topalov instantly replied with this move, and with good reason. The g-file opens with great effect to pressure the now weak g2-pawn, while his center will be bolstered after the trade of bishops on e6. This move might seem strange to some players, but to a Sveshnikov player, or a super-GM like Topalov, it is the only conceivable move.
19.Bxe6
fxe6
20.Nf3
Rg8
Kamsky must hurry and prevent Topalov from expanding in the center too quickly. He still has some resources - but haste is mandatory.
21.c4
f5
22.exf5
exf5
23.Ke2!
A resourceful move! The king's role in the center has ended, and there is no more need for him to defend the c2-square. Additionally, he was starting to become exposed, so it makes sense to transfer his majesty to f1, where it will guard the g2 pawn.
23...Be7
24.Kf1
Kf7
25.Rad1
This is another good moment to analyze what is going on. Black has achieved many things! He fixed his structure and now has a potentially dangerous pawn center. Unfortunately, there is no clear way for him to use it immediately. He will never want to advance e4 and give White the d4 square. So it transpires that a logical plan is to play b5. This can be done immediately, but Topalov shows his class and first plays an important move.
25...Rc5!
This move takes control of the fifth rank, an important element as the 25... b5 variation shows. White is running out of useful moves, so he plays his card... [25...b5!?
26.axb5
axb5
27.Rd5!
This cool moves forces off more pawns than Black wants to trade. The following is only a sample line, but shows the great simplification power White has as his disposal. 27...bxc4
28.bxc4
Kf6
29.c5!
Ke6
30.cxd6
Kxd5
31.dxe7
Rge8
32.Nxh4
Ke6
33.f4
Rc5
34.g4
fxg4
35.hxg4=
And with the last pawn gone the draw is obvious.]
26.b4!
Maybe forced. White uses tactics to resolve some of the tension. [26.Re2
b5
27.cxb5
axb5
28.a5
b4=/+
is definitely NOT what White is looking for.]
26...Rxc4
27.Rxe5
Black has a few ways of dealing with this position. He wants to create as much play as possible, but it seems that White is holding in every line.
27...dxe5
[27...Kf6
28.Ree1
Rxb4
29.Rd4
Rxd4
30.Nxd4=
And Black has no real hopes of winning as he will soon lose an important pawn.; 27...Rxb4
28.Rxf5+
Kg6
29.Ra5
The awkward placement of the rook on a5 would seem to give Black a reason to go for this line, however it is actually difficult to come up with a useful move. The pawns on d6 and h4 are rather weak, and the king will never find shelter. Practically, it is difficult to go for this line as your top choice, but it was definitely worth a try. 29...Rc8!?
30.Re1
Rc7=/+
]
28.Nxe5+
Ke6
29.Nxc4
Bxb4
30.Rb1!
Fixing the pawns on a light square is important, as it will allow White to easily control them, or at least force Black into a major concession if he tries to advance on the queenside.
30...a5
31.Rd1
Rc8
32.Rd4
The weak pawn on h4, the controlled structure on the queenside and the active white pieces give black little hope to win, so black sets up one final trap...
32...Bc3!
33.Rxh4
Bf6
34.Rf4
Bg5
White is at a small crossroads. He could try to gain three (!) passed pawns on the kingside with 35.Rxf5!? or he could play it safe and take a draw. Topalov has simply given Gata the chance to go wrong, but he doesn't bite.
35.Rd4
[35.Rxf5!?
Kxf5
(35...Rxc4
36.Rxg5
Rxa4
37.Rb5+/=
Black might have enough to draw this, but no more.) 36.Nd6+
Ke6
(36...Ke5?
37.Nxc8
Kd5
transposes to Kd5 above.) 37.Nxc8
So now that we reach this position in our minds, we realize that more calculation is necessary. Black has no successful way of trying to corral the knight on c8, so he must lunge toward the queenside - and he has two ways to do this. 37...b5!
Speed is everything. White can't take on b5, but he can clearly catch the pawn. (37...Kd5?
38.Ke2
Now Black's king cannot prevent White's from helping on the queenside, since he cannot afford to lose the b-pawn. 38...Kc5
(38...Kc4?!
39.Nd6+
Kb3
40.Nxb7
Kxa4
41.g3
Kb4
42.Nxa5+-
) 39.Kd3
Kb4
40.Nd6
b6
41.Nb5
Kxa4
42.Kc4+-
And the pawns roll by themselves on the queenside.) 38.Ke2
bxa4
39.Kd3
Bf6
40.Kc4
a3
41.Kb3
Bd4
42.Kxa3
Kd7
43.Ka4
and the position should be drawn. Of course this crazy lines requires quite a bit of calculation, and contains many ways in which one could go wrong. Gata's choice is safe and sound.]
35...Bf6
36.Rf4
Bg5
37.Rd4
Bf6
A tenacious defense by the American. Topalov tried through every flank but eventually came up short of victory, setting up a very anticipated game tomorrow, where Topalov will push with everything he has! 1/2-1/2