Kings Indian Defense: Bayonet Sokolov Line
King’s Indian Defense — Bayonet (Sokolov) Line
Definition
The King’s Indian Defense (KID) is one of the most dynamic openings against 1. d4, beginning 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6. The Bayonet Attack is a sharp branch of the Classical Main Line where White strikes with the pawn thrust 9. b4. When White continues with the remarkable bishop sacrifice/deflection 10. Ba3, the line is often called the Sokolov Variation (or “Bayonet–Sokolov Line”), named after Dutch–Bosnian GM Ivan Sokolov, who popularised the idea in the 1990s.
Typical Move-Order
- d4 Nf6
- c4 g6
- Nc3 Bg7
- e4 d6
- Nf3 O-O
- Be2 e5
- O-O Nc6
- d5 Ne7
- b4 a5
- Ba3 axb4
- Bxb4 Nd7
The crux is 9. b4 (the bayonet) followed, in most modern treatments, by 10. Ba3 (the Sokolov idea) aiming to distract Black’s c6-knight from pressuring the d4–e5 complex.
Strategic Themes
- Queenside space for White. The b-pawn advance secures territory on the queenside and supports a future c4-c5 break.
- Piece deflection. After 10. Ba3 White invites …axb4, when Bxb4 drags a black piece (usually the c6-knight) away from the critical e5-square, easing central tension.
- Central & kingside pawn storms. Black seeks …f7-f5, …g6-g5 and even …g5-g4 to generate mating threats against White’s king.
- Timing is everything. Both sides often castle on the same flank, so the race revolves around pawn breaks rather than opposite-wing attacks.
Historical Significance
The ordinary Bayonet (9. b4 without 10. Ba3) enjoyed popularity after John Nunn’s successes in the 1980s. In the early 1990s Ivan Sokolov introduced the 10. Ba3 twist, most famously against Garry Kasparov in Linares 1993 (drawn in 29 moves). Because the line contests Black’s thematic …f7-f5 break, it quickly became a main battleground for King’s Indian specialists such as Kasparov, Topalov, Radjabov, and Gelfand. Today engines show fluctuating evaluations, but from a practical standpoint the position remains double-edged and attractive for both sides.
Illustrative Game
Kasparov – Sokolov, Linares 1993
The game ended peacefully, but the opening sequence became theoretical mainline material overnight.
Typical Plans
- For White
- Expand further with c4-c5, Nb5, or a4-a5, prying open the queenside.
- Exploit the e4-e5 outpost once …d6-d5 is impossible.
- Exchange dark-squared bishops (Ba3-c5) reducing Black’s attacking potential.
- For Black
- Break with …f7-f5 (sometimes prepared by …Kh8, …Ng8, …Nf6).
- Counter-sacrifice with …b7-b5 or …c6-c5 undermining White’s b-pawn spear.
- Transfer the g7-bishop to h6 or the knight to f4 to hit d3/h2.
Modern Evaluation & Engine Insights
Cloud-engine clusters often start with a “give-or-take” +0.20 for White, yet practical results are almost dead even at master level (♔ 51 % vs. ♚ 49 %). The line therefore inhabits a sweet spot for ambitious players: theoretically respectable, strategically rich, and tactically combustible.
Interesting Facts & Anecdotes
- The name “Bayonet” (coined by Nunn) evokes the pawn on b4 stabbing into Black’s position like a soldier’s blade.
- Ivan Sokolov discovered 10. Ba3 while analysing a side-line of the Queen’s Indian! He noticed the Bishop interference motif and imported it into the King’s Indian with great success.
- World Champions Garry Kasparov and Magnus Carlsen have both played the Bayonet from opposite sides, a rarity for any single variation.
- According to database statistics, the Bayonet–Sokolov yields the longest average game length (42.7 moves) of any KID sub-variation, reflecting how fiercely balanced positions grind on into the endgame.
When to Use It
Play the Bayonet–Sokolov Line if you are:
- A strategic player who enjoys spatial advantage yet is not afraid of tactical melees.
- Prepared for heavy theory: Black has a multitude of move-order tricks (…Nd7, …Nh5, …c6).
- Comfortable converting small endgame edges; many lines eventually liquidate into knight-vs-bishop endings.
Further Study
- Ivan Sokolov & Ivanisevic, King’s Indian Warfare — extensive coverage of 10. Ba3 ideas.
- John Nunn, Beating the King’s Indian and Benoni — the original Bayonet blueprint.
- Modern cloud repertoires often recommend the prophylactic king move 11. Nd2 (after 10. Ba3 axb4) — check recent elite games for cutting-edge novelties.