Nimzo-Indian Defense: Samisch–Keres–Romanovsky

Nimzo-Indian Defense

Definition

The Nimzo-Indian Defense is a hyper-modern chess opening that arises after the moves:
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4.
Black immediately pins the knight on c3, challenges White’s control of the central squares e4 and d5, and prepares rapid development rather than an early pawn occupation of the center.

Typical Move Orders & Main Branches

• 4. e3 – Classical Variation
• 4. Qc2 – Capablanca (or “Classical with Qc2”) Variation
• 4. a3 – Sämisch Variation (see next section)
• 4. Bg5 – Leningrad (or Romanishin) Variation
• 4. f3 – Shirov/Kasparov Variation

Strategic Significance

• Bishop Pair vs. Structure: Black often gives up the dark-squared bishop, damaging White’s queenside pawns in return.
• Flexibility: Black can choose pawn structures resembling Queen’s Indian, Bogo-Indian, Benoni, or French Defense positions, depending on White’s 4th move.
• Hyper-modern Philosophy: Influenced by Aron Nimzowitsch’s ideas of controlling the center with pieces and pressure rather than occupying it with pawns early.

Historical Notes

Introduced by Aron Nimzowitsch in the 1920s, the opening was quickly adopted by World Champions José Capablanca and Alexander Alekhine. It has remained a staple of elite repertoires—used by players from Botvinnik and Karpov to Carlsen and Ding Liren.

Illustrative Mini-Game

Interesting Facts

• The opening is one of only a handful in top-level chess named after an individual player rather than a region or concept.
• Garry Kasparov used the Nimzo-Indian almost exclusively against 1.d4 in his 1985 World-Championship victory over Karpov.
• Machines, from Deep Blue in 1997 to modern engines, consistently rate the Nimzo-Indian as among Black’s very best defences to 1.d4.

Sämisch Variation of the Nimzo-Indian

Definition & Move Order

The Sämisch arises after:
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3.
White immediately asks the bishop to decide: retreat or capture. The main continuation is 4…Bxc3+ 5.bxc3, giving White the bishop pair but saddling him with doubled c-pawns.

Why Play 4.a3?

• Claim the Bishop Pair: Long-term potential on the open board.
• Central Ambition: The move ...Bxc3+ releases White’s e-pawn, enabling rapid e2-e4 pawn breaks.
• Imbalance: White accepts structural weaknesses in exchange for dynamic possibilities—a classic “structure vs. activity” trade-off.

Strategic Themes

• Doubled Pawns but Open Files: The half-open b-file often becomes a highway for a rook.
• Dark-Square Play: The unopposed c1-bishop can grow in strength, aiming at h7 or the long diagonal.
• Central Pawn Mass: After c4-c5 or e2-e4, White tries to seize space and open lines for the bishops.

Typical Continuations

1. 5…c5 6.Nf3 – Classical approach; Black strikes the center.
2. 5…c5 6.f3 – Leads to the Keres–Romanovsky system (next section).
3. 5…d6 6.f3 e5 – A modern, flexible setup for Black.

Historical Tidbits

Named after German master Friedrich Sämisch, who introduced 4.a3 in the mid-1920s. The line became fashionable again thanks to Mikhail Botvinnik (notably his 1945 USSR Championship games) and was later a surprise weapon for Kasparov in the 1980s.

Sample Game

Botvinnik – Janowski, USSR Ch 1945:

Fun Fact

• In databases of elite games, 4.a3 occurs less frequently than 4.e3 or 4.Qc2 but scores approximately one percentage point higher for White in classical time controls.

Keres–Romanovsky Variation (Nimzo-Indian, Sämisch)

Definition & Starting Position

This sub-line begins after:
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. a3 Bxc3+ 5. bxc3 c5 6. f3.
The early pawn to f3 supports an immediate e2-e4, creating a broad pawn center. Black has several replies, the most popular being 6…Nc6 or 6…d6.

Origins of the Name

• Paul Keres (Estonia) tested 6.f3 in the late 1930s.
• Peter Romanovsky (Russia) analyzed similar ideas in the 1920s.
Modern theory credits both, hence “Keres–Romanovsky.”

Strategic Features

• Massive Center: White aims for e2-e4 and d4-d5, leveraging the bishop pair.
• King Safety Concerns: The f-pawn advance weakens the White king; Black frequently counters with …d5 or …Nh5, …Qh4+ ideas.
• Tactical Complexity: Early open files and diagonals lead to sharp play; engines evaluate many positions as close to equality but with high volatility.

Illustrative Line

Mainstream continuation:
6…Nc6 7.e4 d6 8.Bd3 O-O 9.Ne2 Nd7 10.O-O e5
Both sides complete development; White has space, Black relies on piece pressure and breaks like …f5 or …cxd4.

Notable Games & References

• Keres vs Fine, AVRO 1938 – One of the earliest practical tests.
• Kasparov vs Karpov, Linares 1993 – Showed modern treatment with 6…d6 followed by …e5.
• Anand vs Topalov, Corus 2006 – Featured the dynamic …Nh5 and …Qh4+ plan.

Example Mini-PGN

Interesting Nuggets

• In the 1953 Candidates Tournament, Keres scored 3½/4 with this line, reviving it for a new generation.
• The variation often transposes into positions reminiscent of the King’s Indian Saemisch (with colors reversed!), making it attractive to King’s Indian players switching sides.
• AlphaZero’s self-play games have shown a willingness to play both sides of the Keres–Romanovsky, rating it dynamically balanced.