Benoni Defense: Knight's Tour Variation (Modern Benoni)
Benoni Defense
Definition
The Benoni Defense is a dynamic reply to 1. d4, characterised by the moves 1. d4 Nf6 2. c4 c5. Black immediately challenges White’s central presence with the ...c5 pawn thrust, accepting an isolated d-pawn after 3. d5. “Benoni” (Hebrew for “son of sorrow”) was first used in the early 19th century to describe openings in which Black voluntarily takes on a cramped but counter-punching structure.
Typical Usage Over the Board
- Black seeks active piece play and queenside majority counter-play rather than classical symmetry.
- The pawn structure after …d6 and …e6 resembles a half-open Sicilian with colours reversed: White has space, Black has breaks …b5 and …e6–e5.
- White commonly builds a centre with e4 and Nc3, then chooses between calm development or sharp pawn storms with f4.
Strategic & Historical Significance
The Benoni rose to prominence in the 1950s–60s thanks to Mikhail Tal and Bobby Fischer. It remains a favourite of players who enjoy unbalanced positions and complex middlegame tactics.
Illustrative Game
Tal – Fischer, Bled 1959 (Candidates)
Tal won in his trademark sacrificial style, showcasing the opening’s tactical richness.
Interesting Facts
- The Benoni family contains several sub-defences: the Modern Benoni, Benko (Volga) Gambit, Czech Benoni, and Snake Benoni.
- Garry Kasparov used the Benoni to defeat Anatoly Karpov in the 1992 Linares super-tournament, reviving interest at elite level.
Modern Benoni
Definition
The Modern Benoni arises after 1. d4 Nf6 2. c4 c5 3. d5 e6, followed by 4. Nc3 exd5 5. cxd5 d6. Black accepts an IQP-plus structure (isolated d-pawn, backward d6-pawn) in exchange for long-term piece activity and clear pawn breaks …b5 and …f5.
Main Ideas for Both Sides
- White tries to exploit the d6 weakness and extra central space with e4, f4, and sometimes a kingside pawn storm.
- Black fianchettos the king’s bishop (…g6, …Bg7) to attack the e4 pawn and supports …b5 with …a6.
- Endgames usually favour White because of the weak d6-pawn; middlegames often favour Black’s piece activity.
Key Theoretical Branches
- Fianchetto Variation (7. g3) – positional line adopted by Kramnik.
- Taimanov Attack (8. Bg5) – extremely sharp; named after Evgeny Taimanov.
- Four-Pawn Attack (f2-f4 early) – White grabs space, Black seeks counter-blows.
- Knight’s Tour Variation (7. Nd2) – focus of the next definition.
Example Position
After 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. g3 Bg7 8. Bg2 O-O we reach a classic Modern Benoni tabiya with chances for both sides.
Interesting Anecdote
During the 1980 Nice Olympiad, England’s Jonathan Speelman accidentally chose the wrong coloured bishops in his pre-game analysis software and discovered an imaginative sacrifice that evening, leading him to a celebrated victory over GM Ljubojević the next day—proof of the Benoni’s combinational richness.
Modern Benoni: Knight’s Tour Variation
Definition
The Knight’s Tour Variation is a specific line of the Modern Benoni beginning 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. Nf3 g6 7. Nd2. White’s queen knight embarks on a circuit—b1→d2→c4→e3→c2/b6—reminiscent of the mathematician’s knight’s tour problem; hence the nickname.
Strategic Themes
- Flexibility for White: By delaying e4, White keeps the c4-square available and can later play e2-e4, f2-f3, and a kingside expansion.
- Restraining Black: The d2-knight eyes the b3 and c4 squares, making …b5 more difficult to engineer.
- Black’s Plan: Continue with …Bg7, …O-O, and either …Nbd7–e5 or …Re8 followed by …Na6–c7-b5 to break on the queenside.
Model Game
Gelfand – Topalov, Wijk aan Zee 1996
Gelfand’s subtle knight manoeuvre held Black’s counter-play at bay and eventually gave White a superior endgame.
Pros & Cons
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Interesting Facts
- First championed by English GM Jonathan Levitt in the late 1980s.
- ECO code A62 often includes this variation.
- Several engines (e.g., Stockfish 16) now recommend 7…a6 or 7…Na6 over the traditional 7…Bg7 in order to prepare …b5 before White completes the tour.
Knight’s Tour (general chess problem)
Definition
The Knight’s Tour is a classical chess puzzle in which a single knight must visit every square of an otherwise empty board exactly once, returning (depending on the version) to its starting square (closed tour) or ending on a different square (open tour).
Historical Notes
- Traces back at least to the 9th century Arabic mathematician al-Adli.
- Leonhard Euler’s 1759 paper on the tour laid foundations for modern graph theory.
- There are 26,534,728,821,064 distinct tours on an 8×8 board (as proved by De Maesschalck, 1996).
Relevance to Practical Chess
Although purely recreational, the concept inspires opening names—such as the Knight’s Tour Variation—where the knight follows a multi-square voyage reminiscent of the puzzle.
Interesting Tidbit
Grandmasters sometimes set themselves a “knight’s tour” warm-up, solving the puzzle mentally before important games to sharpen calculation skills.