Sicilian Defense OKelly Yerevan System
Sicilian Defense
Definition
The Sicilian Defense arises after the moves 1. e4 c5. Black immediately fights for the d4–square from the flank rather than mirroring White’s pawn in the center. It is the most popular reply to 1. e4 at master level and is catalogued in ECO codes B20–B99.
How it is Used in Chess
- Counter-attacking opening: Black concedes a tiny share of central space in order to obtain an open c-file, dynamic pawn structure, and long-term chances against White’s king.
- Branching system: After 2. Nf3 (most common), Black can choose among numerous set-ups such as the Najdorf (…a6 and …e5 or …e6), Dragon (…d6 and …g6), Classical (…d6, …Nc6, …Nf6), Sveshnikov (…Nc6 and …e5) and the O’Kelly Variation (…a6 on move 2).
- Flexible move orders: Both sides keep many options open; early deviations can lead to quiet positional lines or razor-sharp attacks.
Strategic & Historical Significance
- First champion routinely to adopt the Sicilian was Emanuel Lasker; later it became the cornerstone of the repertoires of Fischer, Kasparov, Anand, and Carlsen.
- Statistically, the Sicilian supplies Black with the highest winning percentage among major answers to 1. e4 in top-level databases.
- Its enormous body of theory has shaped modern computer preparation; engines such as AlphaZero and Leela have expanded its horizons in the 21st century.
Illustrative Example
The Najdorf tabiya above shows the archetypal imbalanced structure: isolated c-pawn vs. central majority, attacking chances for both sides.
Interesting Facts
- Some languages translate “Sicilian” literally (e.g., “Sizilianische Verteidigung” in German) because the opening was popularized by players from Sicily in the 16th-17th centuries, notably Giulio Polerio.
- The opening gave its name to the 1968 Soviet film “Grandmaster,” where the hero wins a thematic Sicilian mêlée.
O’Kelly Variation (Sicilian Defense)
Definition
The O’Kelly Variation appears after 1. e4 c5 2. Nf3 a6. The early …a6 (instead of more common 2…d6, 2…e6, or 2…Nc6) prevents a White knight or bishop from landing on b5 and keeps Black’s structure flexible. ECO codes B28–B29 cover the line. It is named after Belgian grandmaster and former FIDE President Alberic O’Kelly de Galway, who employed it regularly in the 1950s.
Typical Usage & Plans
- After 3. d4 Black often answers 3…cxd4 4. Nxd4 Nf6 intending …e5 (or …e6) and transpositions to Scheveningen-type middlegames where …a6 is already useful.
- Avoiding mainline theory: Because 2…a6 sidesteps the Open Sicilian for one tempo, White must decide on an independent third move (3.c3, 3.c4, 3.Nc3, 3.b3, etc.).
- Flexibility: Black may later choose setups with …e6 and …d5 (aiming for a French-like center) or with …g6 for a Dragon-flavored structure.
Strategic & Historical Notes
- The variation’s original concept was to surprise opponents steeped in Najdorf or Classical theory. IM O’Kelly scored well with it in the 1958 Interzonal.
- It experienced a revival in the 1980s thanks to GM Lev Psakhis and continues to be employed by modern grandmasters such as Baadur Jobava and Ian Nepomniachtchi as a practical weapon.
Model Game
Jobava,N – Nepomniachtchi,I, FIDE Grand Prix, Tbilisi 2015:
The Georgian grandmaster sacrificed a pawn for initiative, typifying the sharp play both sides can achieve in the O’Kelly.
Interesting Tidbits
- Fischer experimented with 2…a6 in a simultaneous display in 1964 but never used it in serious competition.
- The move …a6 on the second move is occasionally called the “Anti-McDonnell” because it prevents a reproduction of the 19th-century Nb5+ idea from the Najdorf’s ancestor, the McDonnell Attack.
Yerevan System (within the O’Kelly Variation)
Definition
The Yerevan System is White’s principal reply to the O’Kelly: 1. e4 c5 2. Nf3 a6 3. c3. By reinforcing d4 in advance, White aims for a solid Alapin-style center while denying Black the immediate freeing plan …cxd4 followed by …Nf6 and …e5. The line is named after the Armenian capital Yerevan, where it featured prominently during the 1996 Chess Olympiad.
Typical Plans
- White:
- Play d4 at a convenient moment, often after 3…Nf6 4. e5 Nd5 5. d4, securing space.
- Establish a Maroczy-like bind with c4 in some versions (especially against …e6 set-ups).
- Maintain a harmonious pawn chain c3–d4–e5 restricting Black knights.
- Black:
- Strike back with …d6 and …Bg4 or …e6 and …d6, targeting the e5 pawn.
- Prepare the thematic …d5 break or queenside expansion …b5 utilizing the pre-advanced a-pawn.
Historical & Practical Significance
- The Yerevan System virtually defines modern theory of the O’Kelly; elite players opt for 3.c3 in roughly 60 % of games after 2…a6.
- Armenian grandmasters, notably Vladimir Akopian and Rafael Vaganian, were early adopters, popularizing it on home turf.
Illustrative Line
White enjoys a space-advantage and freer development. Black counts on the half-open c-file and the lever …d6–d5.
Example Game
Ivanchuk,V – Gelfand,B, Yerevan Olympiad 1996 (the game that helped coin the name):
Fun Facts
- Because the pawn chain c3–d4–e5 resembles a backward letter “զ,” Armenian annotators jokingly call it the “Ayb-Ben-Gim” structure (first three letters of the Armenian alphabet).
- Engines evaluate the starting position of the Yerevan System at roughly +0.20—modest, but enough to entice players seeking a stable edge without entering Najdorf minefields.