When talking about the topic of positional play we cannot omit the theme of Exchange sacrifice. This positional idea was especially popular with World Champion Tigran Petrosian. In modern practice I've seen many Exchange sacrifices in Kramnik's play. While some players resort to it more frequently than others, it seems that in Carlsen's practice it does not appear that frequently. I don't know how statistically correct this fact is, but at least this is the impression I got when going through his games.
The Exchange sacrifice is one of my favorite topics so I could not have written these series without including it! The four examples we will consider today vary in ideas behind the Exchange sacrifice. The first example is a clear-cut Exchange sacrifice for an attack and doubled pawns. This game greatly reminds me of typical Exchange sacrifices on c3 in the Sicilian defense.
The second example features a moment where Carlsen could have sacrificed an Exchange to control the light squares, but chose not to and was forced to give up the rook for the knight a few moves later. The third and fourth examples both involve a strong central pawn pushed far away, where Carlsen gave up the Exchange for the different reasons.
In the following example White pieces are well coordinated on the kingside. Black on the other hand is behind in development. Potentially the rooks on the b-file can be very active once they reach the second and third files. It will take two moves to do that. White's advantage does not only consist of active pieces but also due to a space advantage. The central pawns are menacing - they are ready to move forward and to chase away the black knight and bishop. Because the e7-pawn is missing the dark squares in Black's position are weakened, and this especially true for the d6- and f6-squares.
Carlsen starts a dark-square strategy and kingside attack with a classical Exchange sacrifice on f6. Not only does he eliminate the defender of the king, Nf6, but also messes up Black's pawn structure. Then he masterly exploits the weakness on f6 with a fatal attack.
Carlsen-Nakamura, round 3 of the 2011 London Chess Classic | Photo Ray Morris-Hill
The next example has multiple Exchange sacrifices that appear possible through the span of several moves. In the initial position, capturing the f5-pawn with the rook is quite tempting. The f5-pawn is a weakness and when it is gone all the light squares will be exposed and the Q+B battery gets to work along the b1-h7 diagonal. However, it seems that Black can defend by placing his pieces on dark squares and the white pieces are too far away to cause the black king any damage. Meanwhile, after the b5-break the position will open up and the two black rooks will get to open files to attack the white king.
Carlsen does not sacrifice the exchange on f5 but instead retreats his rook all the way to h1, so it can participate along the first rank if needed. A few moves later the black knight became too dangerous in White's camp and Carlsen ended up giving up an exchange. For compensation he locked up Rb8 and Bc8 temporarily by mounting the knight on b6. Black missed several opportunities to gain a significant advantage and also had to sacrifice an Exchange for Be6, ending up in an equal position.
This example is by no means clear - it is messy and both players made mistakes. Clear-cut Exchange sacrifices do not occur that often, especially in the practice of the current World Champion, who plays with the precision of a surgeon.
Carlsen-Giri, Wijk aan Zee 2012
In the game with Kamsky the World Champion sacrificed the Exchange out of necessity: it was the only non-losing move in the position. Kamsky got a significant initiative rolling in the center and on the kingside, which was mainly supported by a strong e-pawn. After Carlsen gave up the Exchange but got rid of the e-pawn the position was clearly in Black's favor.
It is hard to point out any type of compensation for the lost Exchange. What interesting to me is Carlsen's continuous attempts to trade queens. I think that without queens White can get the king into the game much faster than Black. This is because the black king is stuck on h8 and he needs three moves to get it to a respectable square. For White it will take only one move: Kf2. Also, in the endgame the black pawn weaknesses are probably more felt. Besides, probably Carlsen did not want to give up the e-file for free if he had to retreat queen, after f4, to some other square than e5.
Carlsen-Kamsky, Wijk aan Zee 2012
While in the previous example Carlsen was on the receiving end of a strong attack, in the next example he was the one with a strong passed pawn. He managed to preserve the pawn even if he had to give up an Exchange. Black traded the bishop that could capture the d7-pawn for the rook, so the d7-pawn became untouchable. This tied Black's forces and White had free hands to build up a light-squared attack on the black king and specifically the f7-pawn.
Next week we will see another article of positional methods in Carlsen's play.