Nimzo-Indian: Classical, Pirc, 6.Nf3 Na6 7.g3

Nimzo-Indian: Classical

Definition

The Classical Variation of the Nimzo-Indian Defence arises after the moves 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2. Instead of allowing the characteristic doubled c-pawns after …Bxc3+, White immediately protects the knight on c3 with the queen. The position belongs to the ECO codes E32–E39.

Typical move-order

An illustrative branch is:

• 4…0-0 5. a3 Bxc3+ 6. Qxc3 b6 7. Bg5 Bb7 8. e3 d6 – the traditional “Botvinnik line”.
• 4…c5 5. dxc5 0-0 6. a3 Bxc5 7. Nf3 – the so-called “Karpov System”.

Strategic themes

• Control of e4/e5 squares. By avoiding doubled c-pawns, White keeps more central flexibility but must spend time redeploying the queen.
• Two Bishops vs. structure. Black often gives up the dark-squared bishop early; compensation comes from rapid development and pressure on c4/e4.
• Minor-piece manoeuvres. Knights often re-route via d7–f8–g6 or to e4/c5, while White’s light-squared bishop sometimes lands on d3 after e2–e3.

Historical notes

The classical set-up was a favourite of Mikhail Botvinnik and later became a mainstay of Anatoly Karpov, who demonstrated its strategic richness in multiple World Championship matches against Garry Kasparov (1984–1990).

Example game

Kasparov-Karpov, World Champ. (17), Moscow 1985

Interesting facts

• The nickname “Capablanca Variation” is occasionally applied, because Capablanca used 4.Qc2 against Alekhine as early as 1927.
• The move 4.Qc2 was once considered slightly “too slow”; today it is one of the most theory-heavy branches of the entire Nimzo-Indian.

Pirc

Definition

The Pirc Defence (pronounced “peerts”) is a hyper-modern response to 1.e4, characterised by the moves 1. e4 d6 2. d4 Nf6 3. Nc3 g6. Black allows White to occupy the centre and plans to undermine it later with …e5 or …c5. ECO classification: B07–B09.

Core ideas

• King’s-side fianchetto. …g6 and …Bg7 target d4 and prepare rapid castling.
• Flexible pawn breaks. Black keeps the e- and c-pawns back to hit the centre at the ideal moment.
• Asymmetrical middlegames. Because structures vary (Austrian Attack, Classical, 150-Attack, etc.), rich unbalanced play is common.

Main branches

1. Austrian Attack – 4.f4, 5.Nf3, 6.Bd3, an aggressive pawn storm.
2. Classical System – 4.Nf3 Bg7 5.Be2 0-0 6.0-0.
3. 150/Be3 System – 4.Be3 followed by Qd2 and f3.

Historical significance

Named after Slovenian Grandmaster Vasja Pirc, who refined the defence during the 1930s–50s. It gained wider acceptance in the 1970s thanks to players like Jan Timman and Bent Larsen; modern top-level proponents include Teimour Radjabov and David Navara.

Example game

Kasparov vs. Timman, Tilburg 1991 – a model Austrian Attack encounter.

Trivia

• Because of its hyper-modern roots, the Pirc was once dubbed “the opening that dares you to build a centre”.
• Grandmaster Alexander Beliavsky famously scored 7/7 with the Pirc in the 1984 Soviet Championship qualifier.

6.Nf3 Na6 7.g3 (⁠King’s Indian, Fianchetto …Na6 Line⁠)

Where it arises

The sequence 6.Nf3 Na6 7.g3 is most commonly reached in the King’s Indian Defence, Fianchetto Variation:

1. d4 Nf6 2. c4 g6 3. Nf3 Bg7 4. g3 0-0 5. Bg2 d6  6. Nf3 Na6 7. g3 (diagram after White’s 7th).

Strategic meaning

• Black’s …Na6 idea. The knight heads for c5 or b4, supports …c5, and frees the c-pawn without blocking the bishop on g7.
• White’s double fianchetto. By placing both bishops on g2 and b2 (after b3/Bb2 in some lines) or on g2 and g3 (after Bg2 & g3), White seeks long-range pressure and a solid centre.
• Pawn breaks.
  • Black: …c5, …e5, sometimes …d5.
  • White: d4-d5 space gain, c4-c5 clamp, or e2-e4-e5 central expansion.

Plans for both sides

• Black
  • …c5 followed by …Nc7 and …b5 (the “Petrosian setup”).
  • …e5-e4 thrust if White over-protects the centre.
  • Minor-piece trade on g2 to soften the white king.
• White
  • Maintain the c4-d4 pawn chain, often inserting d4-d5 to seize space.
  • Pressure on the long diagonal a1–h8 after b3 & Bb2.
  • Use the e-file after e2-e4 to attack e7 and f7 once the centre opens.

Historical & modern usage

The …Na6 concept was popularised by Soviet greats such as Tigran Petrosian and Gennadi Sosonko in the 1970s. In modern chess it remains a fashionable, computer-approved line, favoured by Levon Aronian and Peter Svidler.

Model game

Anand – Aronian, Wijk aan Zee 2013

Did you know?

• Because the knight travels from a6 to c5 or b4, commentators sometimes call it the “corkscrew knight”.
• An early …Na6 can transpose to certain Modern Benoni structures if Black later plays …c5 and …e6.