Nimzo-Indian: Classical, 4...O-O 5.Nf3

Nimzo-Indian: Classical, 4…O-O 5.Nf3

Definition

The line arises from the Nimzo-Indian Defence after the moves 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 O-O 5.Nf3. • “Classical” refers to White’s 4.Qc2, a time-honoured attempt to avoid doubled c-pawns while keeping options flexible.
• 4…O-O is Black’s most popular reply, postponing the centre break …d5 or …c5.
• 5.Nf3 develops the king’s knight, reinforces the d4-pawn, and prepares g2-g3 or e2-e4 in various branches.

Typical Move Order

The bare-bones sequence is:

• 1.d4 Nf6
• 2.c4 e6
• 3.Nc3 Bb4  — the hallmark Nimzo-Indian pin
• 4.Qc2 O-O  — Black castles early, declining to define the centre
• 5.Nf3  — “Kasparov’s move”, the modern main line

Strategic Themes

• White
  • Preserves the queenside pawn structure (no doubled c-pawns).
  • Aims for a long-term bishop pair advantage after a3 or g3 systems.
  • Plans e2-e4 or cxd5 to seize central space and eventually a kingside initiative.
• Black
  • Maintains tension, choosing between …d5, …c5 or the flexible …b6 setup.
  • Often exchanges on c3 later, conceding the bishop pair only when it damages White’s structure.
  • Targets the c4-pawn with …c5 or pressurises the e-file after …d5 exd5 Re8.

Historical & Theoretical Significance

The Classical 4.Qc2 was championed by Capablanca and Botvinnik, but it became truly fashionable after Garry Kasparov’s repeated successes in the 1980s. The sub-line with 4…O-O 5.Nf3 is now the critical test of the entire Nimzo-Indian. Major novelties in this branch have steered World Championship preparation from Karpov–Kasparov (1984-90) to Carlsen’s camps today.

Model Games

• Karpov – Kasparov, Moscow WCh 1985, G16 (Kasparov uncorked 9…cxd4! & 11…Bf5 to hold a sharp ending).
• Kasparov – Short, London Candidates 1993 (White showed the attacking potential of the 8.g4 thrust).
• Carlsen – Vachier-Lagrave, Sinquefield Cup 2017 (Illustrates modern treatment with 6.a3 c5 7.dxc5).

Common Plans After 5.Nf3

1. 5…d5 • Main line; play often continues 6.a3 Bxc3+ 7.Qxc3 dxc4 8.Qxc4 b6.
   • Symmetrical pawn structure, bishop pair vs. activity imbalance.
2. 5…c5 • Immediate queenside challenge; can transpose to Benoni-style structures after d5.
3. 5…b6 • The “Romanishin System”, fianchettoing the dark-square bishop and keeping the centre fluid.
4. 5…d6 • Aiming for …e5 and Nimzo-Indian + King’s Indian hybrid positions.

Typical Tactics & Traps

• Double-attack motif: …Bf5 hitting c2 and e4 when White’s queen steps to c2 early.
• Fork on e4: If White pushes e4 too soon, …Nxe4! may exploit the pin on the c3-knight.
• Exchange sacrifice: …Rxc3 in positions with a White queen on c2 and knight on f3 can shatter White’s centre and gain long-term dark-square control.

Interesting Facts & Anecdotes

• In the 1985 World Championship one-third of the games began with the 4.Qc2 line, prompting journalists to nickname it “The Moscow Variation”.
• Karpov’s seconds reputedly spent weeks analysing the obscure 12.Ng5!? in the 5…d5 line before concluding it was harmless—Kasparov played it anyway and drew effortlessly.
• Engines rate the position after 5…d5 as nearly equal, yet the side with the bishop pair scores 54 % in master practice according to MegaBase 2023.