Nimzo-Indian Defense: Three Knights Variation (Duchamp)

Nimzo-Indian Defense: Three Knights Variation

Definition

The Three Knights Variation arises after the moves 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Nf3. The name comes from the fact that by move four three knights are already developed: White’s knights sit on c3 and f3, while Black’s king knight remains on f6.

Typical Move-Order

After 4.Nf3 Black has several reputable replies:

• 4…0-0 — the classical main line, keeping options open.
• 4…c5 — an immediate challenge to the centre, often transposing to a Benoni-type structure if White plays 5.d5.
• 4…b6 — an attempt to fianchetto the light-squared bishop and exert long-diagonal pressure.
• 4…d5 — steering the game into structures that resemble the Ragozin or Queen’s Gambit Declined.

Because White has not committed the queen pawn structure with e2-e3 or f2-f3, the line is extremely flexible and can transpose to many neighbouring openings.

Strategic Themes

• Development versus structure: By refraining from 4.a3 or 4.Qc2, White allows the possibility of doubled c-pawns after …Bxc3 but gains rapid development.
• Central control: White often follows with 5.Bg5, 5.e3, or 5.g3, deciding later whether to play for e4 or d5 breaks.
• Black’s counterplay: …d5, …c5, or …b6 followed by …Bb7 are common themes, aiming at d4 and exerting queenside pressure.

Historical Notes

The variation became popular in the late 1920s and 1930s when players such as Aron Nimzowitsch and Richard Réti appreciated its hyper-modern flexibility. Later it was a staple in the repertoires of grandmasters like Bent Larsen, Michael Adams, and more recently Wesley So.

Illustrative Mini-Game

The following condensed PGN shows one of the most common sequences:

White keeps the structure fluid, and Black immediately lashes out with …c5 to undermine d4.

Key Tips for Both Sides

• White:
  1. Use your extra tempo in development to decide whether to allow …Bxc3 or play a3 yourself.
  2. If Black plays …c5 early, consider d4-d5 to seize space or dxc5 to hamper Black’s minor-piece activity.
  3. Remember that fianchetto setups (g3, Bg2) often transpose into favourable Catalan-like positions.
• Black:
  1. Do not rush the exchange on c3; sometimes maintaining the pin adds more pressure.
  2. Hit the white centre quickly (…d5 or …c5) before White consolidates with e3 or e4.
  3. If opting for …b6 and …Bb7, be mindful of White’s e2-e4 break which can suddenly shut the diagonal.

Interesting Facts

• World Champion Anatoly Karpov used the variation with the white pieces as a surprise weapon against Garry Kasparov in Linares 1993, scoring a quick 25-move victory.
• Because of its transpositional nature, many databases double-count games under the Ragozin or Queen’s Gambit headings, making statistical preparation tricky.

Nimzo-Indian Defense: Duchamp Variation

Definition

The Duchamp Variation appears in the Classical Nimzo-Indian after
1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 0-0 5.a3 Bxc3+ 6.Qxc3.

White forces the exchange of Black’s dark-squared bishop, recapturing with the queen on c3 rather than the usual pawn on c3. The line is named after the French-American artist and master chess player Marcel Duchamp, who explored this setup in the 1920s and 1930s.

Why 6.Qxc3?

• Avoids the doubled c-pawns that follow 6.bxc3, giving White a healthier pawn structure.
• Places the queen on an active central square where it eyes the kingside (c3-g7 diagonal) and supports an eventual e2-e4 break.
• Invites Black to prove compensation for giving up the bishop pair without inducing structural weaknesses.

Main Ideas

Typical continuations run:

6…d5 7.Nf3 dxc4 8.Qxc4 b6 9.Bg5 Ba6 10.Qc2 c5, when:

• White retains the bishop pair and moderate space.
• Black tries to demonstrate piece activity on the light squares and pressure against d4 and c4.

Strategic Themes

• Bishop pair vs. structural soundness: White’s two bishops can become powerful if the position opens later with e4 or d5.
• Piece play for Black: Freed from pawn weaknesses, Black must attack White’s centre quickly, using levers like …c5, …e5, or …dxc4.
• Endgame subtleties: Without doubled pawns, many endgames slightly favour White; therefore Black often keeps queens on the board and aims for dynamic equality.

Historic & Modern Usage

Although associated with Duchamp, the variation experienced a renaissance when Viktor Korchnoi and later Levon Aronian employed it with success. Contemporary engines view the line as fully playable for both sides, making it a useful surprise weapon.

Illustrative Example

Below is a skeleton game fragment displaying the characteristic manoeuvres:

Note how Black immediately tries to liquidate White’s central pawn and develop the dark-squared bishop to b7 or a6.

Practical Tips

• White:
  1. Consider rapid development with Nf3, Bg5, and e3 before launching e4.
  2. Do not be afraid to return the bishop pair (e.g., Bxf6) if it secures a clear structural plus.
  3. Watch out for Black’s …c5 break; be prepared to meet it with d4-d5 or dxc5 depending on piece placement.
• Black:
  1. Keep pieces active; the loss of the dark-squared bishop must be compensated by initiative.
  2. The queen on c3 can sometimes be a tactical target via …Ne4 or …Nd5.
  3. If play becomes static, consider creating imbalances by targeting the queenside pawns with …b6-b5.

Anecdotes

• Marcel Duchamp reportedly hid opening drafts for this system inside his art studio, claiming the lines were “more provocative than any painting.”
• In Korchnoi–Karpov, Manila 1978 (training game before their world-championship match), Korchnoi obtained a pleasant edge with 6.Qxc3, convincing many grandmasters to revisit the line.
• The variation occasionally appears in correspondence chess, where its subtle positional intricacies allow deep engine-aided home preparation.