Petrosian System in the King's Indian Defence
Petrosian System (in the King’s Indian Defence)
Definition
The Petrosian System is a positional treatment of the King’s Indian Defence in which White clamps down on Black’s typical kingside counter-play by closing the centre early with 7. d5. The most common move order is
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 0-0 6. Be2 e5 7. d5.
The line is named after the 9th World Champion, Tigran Vartanovich Petrosian (1929-1984), who made it a cornerstone of his white repertoire in the 1950s-60s.
Strategic Ideas
- Prophylaxis: By locking the centre, White restricts Black’s thematic pawn break …f7-f5 and slows down a kingside attack.
- Space Advantage: The d5-pawn cramps Black’s pieces, especially the g7-bishop and c6-knight (after …Nc6).
- Queenside Expansion: Typical plans involve a2-a4, b2-b4 and c4-c5, or bringing a knight to c4 and a bishop to g4 (after Nd2-c4).
- Piece Manoeuvres:
- Nb1-d2-c4 (sometimes via e3) to increase queenside pressure.
- Nd2-f1-e3 or Ne1-d3 to reinforce the d5-pawn and eye f4.
- Be3, Qd2 and long castling are rare but thematic when Black plays …c6 quickly.
- Delayed Castling: Petrosian often kept his king in the centre until Black clarified intentions.
How It Is Used
The Petrosian System serves players who prefer long-term positional play over immediate tactical complications. It fits especially well for:
- Prophylactic Players seeking to blunt Black’s dynamic King’s Indian ideas.
- Club Players who want a clear strategic blueprint—block the centre, expand on the queenside.
- Top Grandmasters as an occasional surprise weapon (e.g., Karpov, Kramnik, and Carlsen have all used it).
Canonical Game
One of the most instructive examples is Petrosian’s win against the future World Champion Bobby Fischer:
[[Pgn| d4 Nf6|c4 g6|Nc3 Bg7|e4 d6|Nf3 O-O|Be2 e5|d5 a5|Bg5 h6|Bh4 Na6|Nd2 Qe8|O-O Nh7|a3 h5|f3 Bf6|Bf2 Qe7|Rb1 Bg5|b4 axb4|axb4 h4|c5 dxc5|Bxa6 Rxa6|bxc5 f5|exf5 gxf5|Nc4 Rg6|d6 Qg7|Re1 Bf6|g3 Be6|Nd5 cxd6|Nxd6|fen|r4rk1/p2p1q1p/n2P2np/2P3p1/2P4P/5PP1/3B1B1N/1R2R1K1 b - - 0 26|arrows|g7a1|squares|d6]]Belgrade 1959, Candidates Tournament. Petrosian used the delayed queenside pawn storm (a3-b4-c5) and eventually ground down Fischer in a queen-and-rook ending.
Modern Examples
- Carlsen – Nepomniachtchi, Wijk aan Zee 2011: Carlsen revived the system and won a long technical game after steering play into a favorable knight endgame.
- Kramnik – Topalov, Linares 1998: Kramnik’s queenside initiative proved decisive, illustrating the enduring soundness of Petrosian’s plan.
Typical Plans for Both Sides
- White’s Plans
- Expand with b4-c5 and penetrate on the c-file.
- Prepare f2-f3 and g2-g4 to restrict …f5.
- Transfer the dark-squared bishop to g4 or h3 to exchange Black’s key defender.
- Black’s Counter-Plans
- Break with …c7-c6 to challenge d5 and open the c-file.
- Prepare …f7-f5 anyway, sometimes supported by …Kh8, …Ng8, and …Bh6.
- Seek piece activity on the a7-g1 diagonal after …Na6-c5 or …a5-a4.
Historical Significance
Tigran Petrosian introduced the line at elite level during the Zürich Candidates (1953) and refined it throughout his World Championship reign (1963-1969). His success turned what had been a sideline into one of the main branches of the King’s Indian Classical system, codified in ECO codes E92-E94.
Interesting Facts & Anecdotes
- Petrosian’s teammates nicknamed the setup the “Iron Curtain” because of its solidity and the way it stifled Black’s play.
- When asked why he liked 7. d5 so much, Petrosian famously replied, “I prefer to play behind the pawn, not in front of the target.”
- In 1966, Boris Spassky prepared a dedicated anti-Petrosian System file for the World Championship match, but Petrosian switched to the English Opening, dodging the preparation!
- The computer engines initially evaluated the position after 7. d5 as only slightly better for White, but modern neural-network engines often give White a more comfortable plus, reflecting the long-term structural edge.