Nimzo-Indian: 4.e3 O-O 5.Bd3 d5 6.cxd5

Nimzo-Indian: 4.e3 O-O 5.Bd3 d5 6.cxd5

Definition

The move-sequence 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3 O-O 5.Bd3 d5 6.cxd5 marks a branch of the Nimzo-Indian Defence known in modern opening books as the Rubinstein–Koltanowski Variation (ECO codes E52–E53). After White’s 6.cxd5, the Exchange Line, the position usually continues 6…exd5, leading to a symmetrical pawn structure where:

• Black keeps the two bishops but has an isolated hanging-pawn duo on c5/d5 in many lines.
• White enjoys slightly easier development and prospects of a kingside initiative.

Usage in Chess

Practically, the line is chosen by players who want the strategic richness of the Nimzo-Indian without allowing Black’s most dynamic plans based on …c5 in one go. By exchanging on d5 at once, White fixes the central tension, reduces Black’s options, and steers the game toward structures familiar from the Exchange Queen’s Gambit.

Strategic Ideas

• Minor-piece imbalance: Black’s dark-squared bishop can become powerful if allowed to breathe, so White often plays Nge2–g3 or Nf3 to restrain …Bf5/…Bg4 ideas.
• Symmetry with hidden poison: Although the pawn structure is even, Black’s queen bishop is slightly shut in by his own center. White tries to prove that this microscopic edge suffices for long-term pressure.
• Central breaks: Black must time …c5 or …e5 accurately; White eyes e4 or sometimes f3–e4 to seize space.
• Endgame trends: Many pieces are exchanged early; the ending can be pleasant for White because of a safer king and easier minority attack on the queenside.

Historical Significance

The Rubinstein Variation (4.e3) is among the oldest ways to meet the Nimzo-Indian, dating back to Aron Nimzowitsch himself. The sub-line 5.Bd3 was popularised in the 1950s by GM George Koltanowski, while the early exchange on d5 was refined by Karpov and Hubner in the 1970s. Its solid yet flexible character has made it a mainstay in the repertoires of positional greats such as Anatoly Karpov, Vladimir Kramnik and, more recently, Magnus Carlsen.

Typical Continuations

1. 6…exd5 7.Nge2 c5 8.O-O Nc6 9.a3 Bxc3 10.bxc3 Re8 – Black builds harmonious pressure on the dark squares.
2. 6…exd5 7.Nge2 Bd6 (Shirov System) 8.O-O Re8 9.a3 a5 – Black keeps pieces and aims for …c6/…Na6/…Nc7.
3. 6…exd5 7.Nf3 c5 8.O-O Nc6 9.a3 Ba5 – a slightly sharper tabiya giving Black the option of …c4.

Illustrative Example

The following miniature shows both sides’ main ideas:

White fixed the center early but underestimated the latent activity of Black’s bishops; the game illustrates both the promise and the danger of the structure.

Notable Games

• Karpov vs Hubner, Tilburg 1981: A landmark strategic battle where Karpov exploited a slight space edge to convert a long endgame.
• Carlsen vs Gelfand, London Candidates 2013: The World Champion repeated the line to neutralise Gelfand’s Nimzo expertise and eventually ground out a win in 77 moves.
• Kramnik vs Anand, Wijk aan Zee 1998: Demonstrates the latent kingside attacking chances for White after timely f3–e4.

Interesting Facts & Anecdotes

• Because it often transposes to Queen’s Gambit structures, some databases classify 6.cxd5 under QGD statistics; this “identity crisis” can cause headaches for engine book builders.
• George Koltanowski allegedly played 5.Bd3 so often in simuls that students nicknamed the move the “Koltanowski Bishop.”
• Karpov once quipped that exchanging on d5 is like “putting Black on the strategic rack—he either releases the center or lives with a bad bishop.”