Sicilian, Chekhover, 4...a6 5.Be3

Sicilian

Definition

The Sicilian Defence is the opening that begins with the moves 1. e4 c5. By replying to White’s king-pawn with the flank pawn, Black creates an asymmetrical position that immediately fights for the centre without mirroring White’s play. First recorded in a game played in 1594, the Sicilian has grown into the most popular and deeply analysed reply to 1.e4 at every level of chess.

How it is used in chess

Counter-attacking weapon: Black concedes a spatial edge on the kingside in exchange for dynamic counterplay on the queenside and along the c-file.
Opening family: Encompasses dozens of systems such as the Najdorf, Dragon, Sveshnikov, Classical, Scheveningen and Kan, each with its own move-order subtleties.
Repertoire cornerstone: Almost every world champion— from Fischer to Carlsen—has employed the Sicilian in critical games.

Strategic significance

The pawn structure resulting from 1…c5 produces an open c-file, a half-open d-file for White, and an unbalanced pawn island count. These factors give both sides long-term chances:

Black often strikes with …d5 or …b5 to liberate the position.
White frequently aims for a kingside attack using f2–f4, Qd1–f3, long castling, and a pawn storm with g4–g5 or h4–h5.
The imbalance increases the likelihood of decisive results— a fact that appeals to players who want to avoid quiet symmetry.

Historical highlights

Adopted in the 19th century by Louis Paulsen and Carl Jaenisch.
Popularised by Bobby Fischer, who scored +17 =4 –1 with it during his 1971 Candidates run.
In 1997, Kasparov chose the Sicilian (Scheveningen-style) in his famous match versus Deep Blue.

Illustrative game

[[Pgn|Kasparov,Garry–Anand,Viswanathan|World|Chess|Ch.|(Game 10)|1995| e4|c5|Nf3|d6|d4|cxd4|Nxd4|Nf6|Nc3|a6|Be3|e6|f3|b5|Qd2|Nbd7|g4|h6|O-O-O |Bb7|arrows|e2e4,d2d4|squares|c5,b4]]

The game features the ever-sharp Najdorf/English Attack setup, typical of Sicilian complexity.

Interesting facts

Computers initially considered 1…c5 “dubious” in the 1950s. Modern engines now place it among the very best replies to 1.e4.
Statistically, the Sicilian produces more decisive results than any other reply to 1.e4—good news for players who dislike draws.
The name “Sicilian” stems from the Italian priest Pietro Carrera (1573-1647), born near Catania, Sicily, who analysed 1…c5 in his 1617 treatise Il Gioco degli Scacchi.

Chekhover

Definition

The Chekhover Variation is a sideline of the Sicilian that arises after 1. e4 c5 2. Nf3 Nc6 (or 2…d6) 3. d4 cxd4 4. Qxd4. Instead of the normal 4.Nxd4, White immediately recaptures with the queen, inviting Black to gain time by attacking it.

Origin of the name

The line honours Vitold Yakovlevich Chekhover (1908-1965), a Soviet master better known for his end-game compositions. He frequently used and analysed the 4.Qxd4 idea in the 1930s and 40s.

Strategic ideas

Development vs. tempo: White hopes the queen’s central post will not be exploitable and that quick piece activity (often with Bf1-b5+) will compensate for any lost time.
Pawn structure: Because the d-pawn is already gone, exchanges in the centre tend to lead to an isolated queen’s pawn (IQP) for either side, sharpening middlegame play.
Move-order trick: The variation can surprise Sicilian devotees used to Nxd4; many must then navigate unfamiliar early queen moves.

Main continuations

4…Nf6 5.Qe3 – White retreats and keeps the queen on a flexible square, eyeing c5 and g5.
4…e5 5.Qe3 – Black erects a Maroczy-style pawn chain, grabbing space but weakening d5.
4…d6 5.Qe3 – Leads to Scheveningen-type play.

Example game

[[Pgn|Chekhover,V.-Bronstein,David|Moscow|1938| e4|c5|Nf3|Nc6|d4|cxd4|Qxd4|Nxd4|Nxd4|g6|Bf4|Bg7|e5|d6|Bb5+|Bd7|exd6 |Bxd4|dxe7|Qxe7]]

Chekhover himself outplays the future world-title challenger, showcasing the line’s practical venom.

Interesting nuggets

Because the queen moves three times in the first six moves, many modern engines initially dislike White’s setup—yet practical results remain roughly balanced.
Magnus Carlsen dabbled in the Chekhover during online blitz, proving that even top grandmasters keep it in their surprise arsenal.

4...a6 5.Be3

Definition

The move sequence …a6 followed by White’s Be3 on move 5 typically refers to the start of the Sicilian Najdorf English Attack:
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 a6 5. Be3.

Purpose of 4…a6 (Najdorf)

Prevents White’s minor pieces from landing on b5 (knight or bishop), thus controlling d4 and e5 indirectly.
Provides a springboard for …b5 and queenside expansion, often followed by …Bb7 and …Nbd7.
Maintains maximum flexibility—Black commits no central pawn yet, keeping …e5 or …e6 options in reserve.

Idea behind 5.Be3 (English Attack)

White prepares a powerful pawn storm with f2-f3, g2-g4 and h2-h4, typically castling long.
The bishop on e3 eyes the c5-square, bolsters the d4-knight, and supports a future Qd2 battery aimed at h6 or g7.
By not playing 5.Bg5 (the “Poisoned Pawn” main line) White avoids heavy theoretical debates and steers into more strategic—but still sharp— waters.

Tabiya and early branches

After 5.Be3, Black’s main replies are:

5…Nf6 6.f3 e6 7.Qd2 – Classical English Attack.
5…e6 6.f3 Nf6 – Flexibility retained.
5…g6 – Leads to a Najdorf–Dragon hybrid (“Dragdorf”).

Historical significance

The 4…a6 5.Be3 line exploded in popularity in the late 1980s when English grandmasters like John Nunn and Nigel Short used it successfully—hence the name “English Attack.” It became the battleground for the 1990s rivalry between Garry Kasparov and Vishy Anand, and remains a staple in modern grandmaster practice.

Illustrative miniature

[[Pgn|Adams,Michael–Shirov,Alexei|Dos|Hermanas|1999| e4|c5|Nf3|d6|d4|cxd4|Nxd4|a6|Be3|Nf6|f3|e6|Qd2|b5|g4|h6|O-O-O|Bb7|h4|d5 |Bh3|dxe4|g5|hxg5|hxg5|Nd5|g6|Nxe3|gxf7+|Kxf7|Qxe3]]

Interesting facts

Once dubbed “theory light,” the English Attack has ballooned into one of the most computer-analysed battlegrounds; cloud databases now contain millions of games starting from this position.
Despite its name, Chinese prodigies Wei Yi and Ding Liren have scored some of the best winning percentages as White.
Black’s experimental attempts—such as the early pawn sacrifice 6…e5!?—continue to generate fresh ideas, showing the line’s inexhaustible depth.