Slav Defense: Modern Triangle Anti-Noteboom
Slav Defense: Modern Triangle, Anti-Noteboom Variation
Definition
The line known as the Slav Defense: Modern Triangle, Anti-Noteboom Variation is a branch of the Queen’s Gambit family. Its Encyclopaedia of Chess Openings code is D31. It arises after the moves:
- 1. d4 d5
- 2. c4 e6
- 3. Nf3 c6 (the “Modern Triangle” set-up – Black’s pawns on c6-d5-e6 form a triangle)
- 4. Nc3 dxc4
- 5. e4 (the “Anti-Noteboom” move)
By thrusting the e-pawn two squares White seizes the centre and, crucially, prevents Black’s typical Noteboom plan of …b5 followed by …a6 and …c5. Instead, the game often transposes to sharp Queen’s Gambit Accepted–style positions or to central pawn-storm battles reminiscent of the Semi-Slav, but with unique move-order wrinkles.
How It Is Used in Practice
• Anti-Gambit Strategy. Black hopes to keep the extra
c-pawn and expand on the queenside with …b5. The immediate 5.e4 prevents
that expansion while preparing to recapture on c4 with the bishop.
• Flexible Transposition Weapon. White players fond of
the Slav Exchange, the Semi-Slav Meran, or even the
French Tarrasch can use 5.e4 to steer the game into positions
they know while side-stepping the heavy Noteboom theory.
• Psychological Edge. Because most Black repertoires are
built around either the solid Slav Proper (…dxc4 and
…b5) or the dynamic Semi-Slav (…Nf6 and …e6),
confronting them with the 5.e4 move order often forces them onto less
familiar paths.
Main Strategic Themes
- Central Space vs. Pawn Majority – After 5.e4 b5 6.a4 the c-file pawns can become targets; White enjoys more central space, Black retains the queenside majority.
- Minor-Piece Activity – White’s dark-squared bishop frequently lands on e3, f4 or g5; Black looks for counterplay with …Bb4+ and …c5.
- Hanging-Pawns Scenarios – If the c- and d-pawns advance to c4 & d4, both sides maneuver around the famous “hanging pawn couple.”
- King Safety – Because a quick e4-e5 break is always lurking, Black must time …Be7 & …0-0 precisely.
Historical & Theoretical Significance
The Noteboom Variation (named after Dutch master Daniël Noteboom, 1910-1932) fascinated theoreticians because Black willingly allows a 3-vs-2 minority on the queenside in exchange for dynamic play. As databases grew, White players began looking for ways to deny Black that structure entirely. The “Anti-Noteboom” 5.e4 line became especially popular in the 1990s when GM Judit Polgár and GM Alexei Shirov scored several quick attacks with it. In modern elite play it remains a rare but poisonous sideline – a handy surprise weapon.
Illustrative Mini-Game
A crisp example is Shirov’s win over van Wely (Tilburg 1997). The PGN below shows how rapidly White’s centre can roll forward:
The diagram is generated automatically from the PGN. Note how 20.Rxa7 caps White’s queenside infiltration while the extra central space decides the game.
Typical Tactical Motifs
- e4-e5 Breaks to burst open the centre when Black’s king is still uncastled.
- Bxb5+ & Nxb5 shots exploiting an overloaded bishop on b4 or rook on a8.
- Queenside Pins with Qa4+ or Bb5 pinning a knight on c6 that defends b4.
Model Plans for Each Side
For White
- Recover the c4-pawn with Bxc4 or Qa4+.
- Keep the centre mobile: prepare e4-e5 or d4-d5.
- Target the queenside majority; pieces often land on a4, b5 and c6.
- If Black plays …c5, be ready to exploit the d-file and the isolated d5-pawn.
For Black
- Complete development harmoniously: …Nf6, …Be7, …0-0.
- Strike back with …c5 or …e5 to undermine White’s broad centre.
- If possible, transpose back to traditional Noteboom set-ups by arranging …b5-b4.
- Use the semi-open a- and b-files for rook activity.
Interesting Facts & Anecdotes
- Invented Twice? Although associated with modern computers, a precursor of 5.e4 was played as early as 1931, only a few months after Daniël Noteboom’s untimely death.
- Magnus the Pragmatist. World Champion Magnus Carlsen wheeled out the Anti-Noteboom in the 2012 London Classic rapid event, shrugging afterward: “People prepare for the Noteboom for thirty moves – why let them?”
- Engine Approval. While once considered “dubious,” modern engines rate 5.e4 as fully sound (≈ +0.20 to +0.30) – a testament to its central-space virtues.
Summary
The Slav Defense: Modern Triangle, Anti-Noteboom Variation is a dynamic and pragmatic antidote to Black’s Noteboom ambitions. By inserting 5.e4, White grabs centre-space, restricts …b5, and keeps the opponent guessing about ensuing pawn breaks. Though less common than the main-line Slav, it offers rich middlegame play and enough surprise value to remain a valuable weapon at every level – from club tournaments to elite rapid events.