1.d4 d5 c4 c6
Slav defense is one of the most solid defenses against the queen's pawn first move, creating a strong and sometimes impregnable pawn chain that stretches from b7 to f7, with d5 square at its peak. In general black also wants to get his light-squared bishop out to f5 or g4, so as not to be bounded by this pawn chain and to exert pressure on white's center. On the other hand, black is not ambitious in a sense of challenging white's central domination early in the opening with pawn breaks such as c5 or e5 that we see in some other openings, so white usually enjoys a slight pressure within the first 5-15 moves. However, once black fully develops his forces behind the b7-d5-f7 fortress, he will be equally ready to fight for the center as white. Thus, white needs to exploit his temporary spatial (and of course, the first move) advantage if he wishes to create problems for black.
White has many possible ways to fight against black's setup, so let's quickly look at the most common ones:
1) exchange variation, 3.cxd5
2) flirting with the Meran setup with 3.Nc3 Nf6 4.e3
3) slow play with 3.Nf3 Nf6 4.e3 or 4.Qb3/Qc2
4) direct play with 3.Nf3 Nf6 4.Nc3
Every approach has its merits, especially depending on your opponent, tournament situation etc. However, I have always been an advocate of principled play with white, meaning looking for direct and challenging lines, if possible. It should then come as no surprise that I will recommend a repertoire against the Slav based on the direct approach (number 4). The main advantage of this approach is that we are not letting black play desired Bf5 or Bg4 for free (he will need to make some sort of a concession if he wants to do that), which he can do in approaches 1-3. In addition, we discourage black from playing Schlechter variation (4...g6) and we reserve an option to develop our dark-squared bishop to f4 or g5 in some instances. 3.Nf3 Nf6 4.Nc3 By developing both knights to their most natural squares white has remained flexible for the moment. In contrast with approaches 2) and 3), here we have ommited playing e2-e3 yet, so our dark-squared bishop can be utilized on the c1-h6 diagonal in some lines. Truth be told, dark-squared bishop flexibility is promised by approach 1) as well, but an important difference is that the exchange on d5 gives black a natural developing square c6 for his knight and he does not have this luxury when white employs the direct approach. The only drawback of white's direct approach is apparent weakness of c4 pawn, which black tries to use to his advantage in certain lines.
At this junction, black has to choose his plan. Ideally, he would like to develop his light-squared bishop to f5, but that does not work well right now due to 5.cxd5 cxd5 and 6.Qb3 targeting both b7 and d5 pawns.
After: 4...dxc4 we reach the starting position of this database
The only drawback of direct approach with 3.Nf3 and 4.Nc3 is c4 pawn being unprotected. In the Classical Slav, black immediately tries to take advantage of that fact by taking the pawn and threatening to hold on to it with b7-b5 in case of 5.e4 or 5.e3. Practice has shown that the best way for white to fight for advantage is to deny black this option with:
5.a4 (Alternatives are: 5.e4 b5 6.e5 Nd5 7.a4 and 5.e3 b5 6.a4 b4 7.Na2 (7.Nb1 Ba6 with a complex play) e6 8.Bxc4 Be7 with playable but objectivly equal positions in both of the cases. As black will not do well by trying to hold on to his extra pawn by means other than b7-b5 (ideas like Be6 or Qa5-b4 are too sketchy), he is best advised to continue his development. Before we look at his developing options, let us take stock of the previous move. Black has given up the control of e4 square by playing dxc4, while white has done the same with b4 square by playing a2-a4. Therefore, both sides have made a small concession. However, compared to a move ago (position after 4.Nc3), black is now able to develop his c8-bishop freely because white does not have the annoying Qb3 any more. Since he has given up control of the e4 square by playing dxc4, the most logical continuation is to take this square under control with 5...Bf5 and that is indeed the most common move in this position.
5...Bg4 developing the bishop to a more active square and discouraging e2-e4 by indirect means.
This provocative variation captured attention of many Soviet GMs in the old time as the main alternative to 5...Bf5. The idea of Bg4 is, apart from developing a piece, to weaken white's control of d4 square.
5...Na6 - preparing to bring the knight to the weakened b4 square (normally the bishop goes there and the knight to d7).
The knight is obviously headed to b4 square. While this square is comfortable for the knight, black is giving white the golden opportunity to seize the center with e2-e4.
5...a5 - which is a solid fighting line with little theory compared to other lines.
All these less challenging variations will be covered in Chapter 1 to give you a taste of the typical Classical Slav positions, before we move on to the more complex theoretical material in the following chapters.
5...e6 preparing c6-c5 break, aiming for the Queen's gambit accepted kind of position is the most serious alternative to the main line.
This hybrid variation was first played in 1930-is, but was left for dead after Alexander Alekhine (see in a picture below) won a few games against it in a very convincing fashion. It was revived by Vladimir Kramnik's analysis team for the World Championship match against Leko in 2004, where Kramnik scored an effortless draw with black. Soon thereafter, it began gaining popularity among strong players as a very solid weapon. Alekhine considered the move dubious due to 6.e4, but things are not so simple today as they were in 1935.
From this chapter I am starting investigation of the main line: 5...Bf5 White now has 3 possibilites: 6.Ne5, 6.e3 and 6.Nh4. We recommend the first one:
The alternatives: 6.e3 is a slower move, aiming to complete development with Bxc4 and 0-0 before undertaking any actions in the center. 6...e6 7.Bxc4 Bb4 8.0-0 0-0 Then white usually fights for e4 square with 9.Qe2 Nbd7 10.e4 Bg6 where black's solidity and lack of weaknesses compensate for white's spatial advantage.
6.Nh4 is an exciting alternative, though less principled than the first two. Black usually play: 6...Bc8 7.e3 (7.e4 e5!) Bg4! with a complex play or 6...e6 and after: 7.Nf5 exf5 he gets a pawn structure where bishop on f5 is replaced with the pawn and black's good control of central squares yields him reasonable chances in the arising middlegame positions
Our main line is: 6.Ne5 The idea of this move is twofold: taking the c4 pawn with the knight and preparing f3, e4 (sometimes g3, Bg2, e4) to gain control of the vital e4 square.
Compared to 6.e3, which is the main alternative, this is a more ambitious, sort of a high risk/high reward approach.
Against 6.Ne5, Black has two natural moves: 6...Nbd7 and 6...e6, plus 6...Na6, which is a decent sideline.
In this chapter we investigate the variation 6...e6 7.f3 c5
This modest continuation was tested in Wch matches between Topalov and Kramnik (2006) and Topalov and Anand (2010). Black does not even pretend to get anything more than a draw in this line (perfect for Wch matches), so white should thread carefully if he wants to get the full point.
Variation after 6.Ne5 e6 7.f3 Bb4 is analyzed here.
This variation, invented by late Andre Cheron - a famous endgame composer, leads to some very interesting chess. Black is ready to sacrifice a piece after the most principled move 8.e4. An enormous body of theory has accumulated over the years in the line starting with 8.e4 Bxe4 9.fxe4 Nxe4 and studying it properly takes a lot of time, which may not be the most practical solution. I remember once Alexander Khalifman said it took him two weeks to analyze a particular branch of this variation to find equality for black. Secondly, I am not convinced that white can even count on any tangible advantage if black plays the best moves. Even if he does, positions that arise are quite unusual and seem to be easier to play for black as he has a clear plan and white is not well co-ordinated. Therefore, I have decided to recommend a bit less theoretical, though perfectly playable: 8.Nxc4 0-0 9.Kf2 This peculiar idea is less explored than the main line with 8.e4, but is nevertheless putting black under a serious test as to how to deal with e2-e4.
Here I analyzed all 6th move sidelines after 6.Ne5
The major one is 6...Na6
Among the alternatives to Nbd7 and e6, this is the most prominent one. Black aims to bring his knight to b4 and in some lines tease white with Nc2/Bc2 ideas.
After 6.Ne5 the main line is 6...Nd7 7.Nxc4 Here we have another crossroads for black with two major roads and one side-road. The move 7...Nb6 is analyzed here (7...Qc7, 7...Nd5 and 7...e6 are analyzed in the next chapters)
his flexible variation (especially connected with the subsequent a7-a5) was not at all popular until early 2000's when Ivan Sokolov (see in a picture below) found some interesting ideas for black. Over the years, it has become a reliable alternative to 7...Qc7, at times even surpassing it in popularity.
Before we move to 6.Ne5 Nbd7 7.Nxc4 Qc7 we have to mention two rare alternatives 7...Nd5 and 7...e6
This is actually not that bad, though it is not at all challenging for white, in my opinion.
The main line arise after: 6.Ne5 Nbd7 7.Nxc4 Qc7
This is the main line and probably the most challenging one for our direct approach. Black wants to break up white's pawn center immediately with e7-e5. However, white can use the position of Qc7 to his advantage with:
8.g3 e5 9.dxe5 Nxe5 10.Bf4 (quite unpleasant pin) 10...Nfd7 11.Bg2 this is one of the main tabyas of Slav Defence. In this chapter we will deal with the move 11...f6
In this chapter we will quickly cover all the minor lines in 6.Ne5 Nd7 7.Nxc4 Qc7
The variations: 8.g3 e5 9.dxe5 Nxe5 10.Bf4 Rd8 and 8.g3 e5 9.dxe5 Nxe5 10.Bf4 Nfd7 11.Bg2 Be6 are playable but failed to equalize.
This is an old move. Black wants to alleviate the pressure on e5 without playing f7-f6 which weakens the kingside.
In the final chapter we will analyze the most critical line in a Classical Slav:
6.Ne5 Nd7 7.Nxc4 Qc7 8.g3 e5 9.dxe5 Nxe5 10.Bf4 Nfd7 11.Bg2 brings us to the tabiya of Classical Slav. Here Morozevich (see in a picture below) came up with fantastic 11...g5!?
This move has given white quite a few headaches over the years. However, by now a reliable path to advantageous positions for white has been found with 12.Ne3, which incidentally, is also the move that Garry Kasparov used to beat Morozevich, when he faced 11...g5!? for the first time in 2001.