Slav Defense: Modern Alapin, Czech, Krause, Carlsbad
Slav Defense
Definition
The Slav Defense is a solid reply to the Queen’s Gambit that begins 1. d4 d5 2. c4 c6. Black immediately supports the d5-pawn with the c-pawn instead of the e-pawn (as in the Queen’s Gambit Declined), keeping the light-squared bishop inside the pawn chain.
Typical Move-Order
Core position after four natural moves:
1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 or 4…e6
Strategic Themes
- Sturdy pawn structure: The c6–d5 chain is hard to undermine early.
- Freeing the light-squared bishop: By avoiding …e6, Black can develop the bishop to f5 or g4.
- Minority attack: If the game reaches the Carlsbad pawn structure, White often advances b2-b4-b5 to weaken Black’s queenside.
- Flexibility: Black chooses between solid (…e6), dynamic (…dxc4 followed by …b5), or hybrid setups.
Historical Notes
Analyzed by Czech masters in the late 19th century, the Slav rose to prominence after its adoption by World Champions Alekhine and Botvinnik. Today it is a cornerstone of elite repertoires—Kramnik, Caruana, and So have all scored heavily with it.
Famous Example
Kasparov – Kramnik, Linares 1993. Kramnik’s precise handling of the Slav set the stage for his later match strategy against Kasparov in 2000.
Interesting Facts
- The name “Slav” honors early analysis by Czech and Slovak players, not the broader Slavic world.
- AlphaZero’s self-play games showed a preference for the Slav over the Queen’s Gambit Declined.
Modern (or Modern Slav) Variation
Definition
Within the Slav, the Modern Variation arises after 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 a6. The early …a6 prepares …dxc4 and …b5, grabbing the c4-pawn and keeping it.
Key Ideas
- Queenside expansion: The pawn trio …a6–b5–c6 restrains White’s minority attack.
- Delayed development: Black postpones …Bf5 until the queenside is secure, sometimes fianchettoing the bishop to b7.
- Central tension: White decides between 5. c5 (space-grab), 5. a4 (preventing …b5), or 5. e3 aiming for quick development.
Historical Significance
First championed by Alekhine (e.g., Alekhine–Grigoriev, Moscow 1919), the line received a renaissance when V. Kramnik used it in his 2000 World Championship victory, causing a surge of theoretical interest.
Illustrative Mini-Game
Black keeps a rock-solid structure while solving the light-squared-bishop problem.
Trivia
- Engines once criticized 4…a6 as “too slow”; today it ranks among the most trusted Slav systems at 2700+ level.
Alapin Variation (in the Slav)
Definition
The Alapin Variation of the Slav appears after 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. e3. Named after Russian theoretician Semyon Alapin, White forgoes Nc3 to build a strong center with e3–e4.
Plans for Both Sides
- White: Play 5. Nc3 or 5. Bd3 and quickly push e3-e4, exploiting the temporarily passive light-squared bishop on c8.
- Black: Counter by (a) taking on c4 and holding the extra pawn, or (b) striking in the center with …e5 or …c5 after rapid development.
Model Continuation
1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. e3 Bf5 5. Nc3 e6 6. Nh4 Bg4 7. Qb3 Qb6 (sharp line studied deeply by Alapin in 1902).
Historical Context
Although eclipsed by 4. Nc3 in master practice, the Alapin was a favorite of Smyslov and Uhlmann. Modern rapid specialists use it for surprise value.
Interesting Fact
- The same analyst, Alapin, lends his name to openings in the Sicilian (2. c3) and French (2. d4 d5 3. Be5?!), showing his wide-ranging experimentation.
Czech Variation (of the Slav)
Definition
The Slav’s Czech Variation features …Na6, usually reached via 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4 Na6. The knight supports …Nb4, pressuring c2 and d3 while retaining the extra c-pawn.
Strategic Points
- Keeping the pawn: …Na6–b4 discourages Bxc4 recapture.
- Queenside imbalance: White often gains space with e4; Black counters with …Bg4 and …e5.
- Flexibility: The knight may reroute via c7 to e6 or d5, echoing ideas from the Chigorin Defense.
Origin & History
Analyzed by Czech masters Hromádka and Treybal (1920s), the variation appeared in Rubinstein’s games and remains an off-beat but playable option.
Example Snippet
Krause Variation (Slav)
Definition
Named after German Master Paul Krause, this line starts 1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 dxc4 5. a4 Bf5. Black develops the bishop before locking it behind …e6, intending to hold the c4-pawn with …b5.
Main Ideas
- Piece activity: The early Bf5 provokes e2-e3, hindering White’s dark-squared bishop.
- Pawn grabbing: 6. e3 e6 7. Bxc4 Bb4 places pressure on e4 and c3.
- Dynamic play: If White plays 6. Ne5, Black counters with …Nbd7 and queenside expansion.
Classic Game
Lasker – Capablanca, St. Petersburg 1914 (pre-tournament training). Capablanca equalized effortlessly with the Krause, influencing his later adoption of solid queen’s pawn structures.
Interesting Tidbit
- In some modern databases, 5…Bf5 scores better for Black than the once-fashionable 5…e6.
Carlsbad Variation / Carlsbad Structure
Definition
More a pawn structure than a pure opening, the Carlsbad arises from Queen’s Gambit or Slav lines after 1. d4 d5 2. c4 c6 3. cxd5 cxd5 (or analogous). The defining feature is:
- White pawns: d4 and c2 (sometimes e3 and b2)
- Black pawns: d5 and c6
Strategic Hallmarks
- Minority attack: White advances b2-b4-b5 to create a target on c6.
- Kingside play: Black may generate counterplay with …f7-f5-f4, attacking White’s king.
- Endgame edge: The weak c6-pawn can be fatal in simplified positions.
Historical Origin
First studied at the 1923 Carlsbad (Karlovy Vary) tournament— hence the name—where players like Nimzowitsch and Capablanca debated the structure.
Model Game
Botvinnik – Rubinstein, Nottingham 1936. Botvinnik’s textbook minority attack became an endgame classic.
Fun Facts
- Nimzowitsch coined the term “minority attack” while annotating Carlsbad-type games.
- Endgame manuals often start their pawn-structure chapters with the Carlsbad because its plans are so thematic.