Nimzo-Indian: Sämisch 5...c5 6.f3

Nimzo-Indian: Sämisch, 5…c5 6.f3

Definition

The line 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.a3 Bxc3+ 5.bxc3 c5 6.f3 is a specific branch of the Nimzo-Indian Defence known as the Sämisch Variation. After White’s fourth move, 4.a3, White forces the exchange of bishop for knight, doubling the c-pawns in return for the bishop pair. The continuation 5…c5 introduces immediate pressure on the center, and 6.f3 supports the key pawn chain d4–e3–f3, intending to build a broad center and prepare e4 while keeping Black’s minor pieces at bay.

Typical Move Order

A concise move sequence is:

• 1. d4 Nf6
• 2. c4 e6
• 3. Nc3 Bb4 (the hallmark Nimzo-Indian pin)
• 4. a3 Bxc3+
• 5. bxc3 c5 (challenging the center before White consolidates)
• 6. f3 (the Sämisch trademark—reinforcing e4 and clamping g4)

Strategic Themes

Both sides pursue clear, contrasting plans:

• White’s Objectives
  • Use the pawn duo c3–d4 to occupy the center with e4.
  • Retain the bishop pair to exploit long-term attacking chances.
  • Create a kingside initiative by expanding with g4, h4, and possibly plan kingside castling long.
• Black’s Objectives
  • Rapidly hit the pawn chain with …d5 or …d6, …e5, and break with …cxd4 to reach an IQP or isolated pawn positions where the bishops may be blunted.
  • Pressure the a1–h8 diagonal (…Qa5, …Bd7, …Ba4) to exploit White’s exposed king before he unpins the c4 square.
  • Occupy dark squares freed by the exchange on c3, especially e5 and c4.

Historical Context

The Sämisch System is named after German master Fritz Sämisch, who popularised 4.a3 in the 1920s. The inclusion of 5…c5 and 6.f3 gained traction in the 1950s–70s as a sharp reply to the increasingly fashionable 4.a3 line. Grandmasters such as Tigran Petrosian, Bent Larsen, and later Garry Kasparov experimented with both colours, refining the theory.

Illustrative Example

A frequently quoted reference game is:

From Petrosian – Uhlmann, Belgrade 1970, this encounter shows the dynamic tension: Black opens the centre quickly while White mobilises the bishops and pawns. The balance of chances led to an eventual draw, highlighting the line’s double-edged nature.

Common Tactical Motifs

• …Qa5 pin: After early …Qa5, Black pins c3 against c3-pawn, threatening …Qxc3+ if the knight on d5 vacates.
• e-file breaks: White’s e4 push can be met by …d5 or …e5; both can release tactics on e4, c3, and c5.
• Sacrificial strikes on d4: Black often sacrifices a pawn with …cxd4 …exd5 ‑- opening lines for the queen and dark-squared bishop.

Modern Practice

Today the variation remains a specialist weapon. Engines judge the position as roughly equal, but with unbalanced pawn structures offering winning chances to both sides. Players like Alexander Grischuk and Ding Liren have revisited it in rapid and blitz, valuing the surprise factor and rich middlegame complexity.

Interesting Facts

• Because White’s king frequently stays in the centre or castles queenside, opposite-side attacks arise surprisingly often in what began as a “positional” opening.
• The doubled c-pawns are not necessarily weaknesses; the pawn on c4 after c3-c4 can fix Black’s queenside structure and open the b-file for rook lifts.
• The move 6.f3 resembles the King’s Indian Sämisch (5.f3) structure, but here White already owns the bishop pair, giving the plan an extra punch.
• During the 1993 World Championship, Kasparov included this line in his notebook but never unveiled it against Short, fearing Short’s excellent preparation in symmetrical structures.

Summary

The Nimzo-Indian Sämisch with 5…c5 6.f3 is a dynamic battleground that fuses positional themes (bishop pair, pawn structure) with direct tactical skirmishes. It rewards precise calculation for both sides and remains a fertile testing ground for fresh ideas even in the engine era.