Introduction to Sicilian

The Sicilian Defence is a chess opening that begins with the following moves:

1. e4 c5

The Sicilian is the most popular and best-scoring response to White's first move 1.e4. 1.d4 is a statistically more successful opening for White due to the high success rate of the Sicilian defence against 1.e4.New In Chess stated in its 2000 Yearbook that of the gamesin its database, White scored 56.1% in 296,200 games beginning 1.d4, but 54.1% in 349,855 games beginning 1.e4, mainly due to the Sicilian, which held White to a 52.3% score in 145,996 games.

17% of all games between grandmasters, and 25% of the games in the Chess Informant database, begin with the Sicilian.Almost one quarter of all games use the Sicilian Defence.

Grandmaster John Nunn attributes the Sicilian Defence's popularity to its combative nature; in many lines Black is playing not just for equality, but for the advantage. The drawback is that White often obtains an early initiative, so Black has to take care not to fall victim to a quick attack. Grandmaster Jonathan Rowson considered why the Sicilian is the most successful response to 1.e4, even though 1...c5 develops no pieces, and the pawn on c5 controls only d4 and b4. Rowson writes:

To my mind there is quite a straightforward explanation. In order to profit from the initiative granted by the first move, White has to make use of his opportunity to do something before Black has an equal number of opportunities of his own. However, to do this, he has to make 'contact' with the black position. The first point of contact usually comes in the form of a pawn exchange, which leads to the opening of the position. … So the thought behind 1...c5 is this: "OK, I'll let you open the position, and develop your pieces aggressively, but at a price – you have to give me one of your center pawns."

— Jonathan Rowson, Chess for Zebras: Thinking Differently About Black and White.

General concepts

By advancing the c-pawn two squares, Black asserts control over the d4-square and begins the fight for the centre of the board. The move resembles 1…e5, the next most common response to 1.e4, in that respect. Unlike 1...e5, however, 1...c5 breaks the symmetry of the position, which strongly influences both players' future actions. White, having pushed a kingside pawn, tends to hold the initiative on that side of the board. Moreover, 1...c5 does little for Black's development, unlike moves such as 1...e5, 1...g6, or 1...Nc6, which either develop a minor piece or prepare to do so. In many variations of the Sicilian, Black makes a number of further pawn moves in the opening (for example, ...d6, ...e6, ...a6, and ...b5). Consequently, White often obtains a substantial lead in development and dangerous attacking chances.

Meanwhile, advancing a queenside pawn has given Black a spatial advantage there and provides a basis for future operations on that flank. Often, Black's c5-pawn is traded for White's d4-pawn in the early stages of the game, granting Black a central pawn majority. The pawn trade also opens the c-file for Black, who can place a rook or queen on that file to aid their queenside counterplay.

Open Sicilian: 2.Nf3 

Over 75% of games beginning with 1.e4 c5 continue with 2.Nf3, after which there are three main options for Black: 2...d6, 2...Nc6, and 2...e6. Lines where White then plays 3.d4 are collectively known as the Open Sicilian, and result in extremely complex positions. White has a lead in development and extra kingside space, which White can use to begin a kingside attack. This is counterbalanced by Black's central pawn majority, created by the trade of White's d-pawn for Black's c-pawn, and the open c-file, which Black uses to generate queenside counterplay.

Closed Sicilian

 

2.Nc3 is White's second most common move  responding to 1.e4 c5.

 

Alapin Variation: 2.c3 

2.c3 is the Alapin Variation or c3 Sicilian. Originally championed by Semyon Alapin at the end of the 19th century, it was revived in the late 1960s by Evgeny Sveshnikov and Evgeny Vasiukov. Nowadays its strongest practitioners include grandmasters Sergei Tiviakov and Eduardas Rozentalis.

 

Grand Prix Attack: 2.f4 

2.f4 is the Grand Prix Attack or McDonnell Attack: the latter name stems from the 14th match game played in London in 1834 between Alexander McDonnell and Charles Louis Mahé de La Bourdonnais, won by Black. According to Jeremy Silman and others, Black's best reply is 2...d5 3.exd5 Nf6!, the Tal Gambit, which has caused the immediate 2.f4 to decline in popularity.^[46] White may decline the gambit with 3.Nc3, called the "Toilet Variation", so named after its reputed place of invention.^[47] A less common option is 2...e6, as La Bourdonnais played against McDonnell. Players usually enter the Grand Prix Attack nowadays by playing 2.Nc3 first before continuing 3.f4. The modern main line runs 2.Nc3 Nc6 3.f4 g6 4.Nf3 Bg7. Here White can play the positional 5.Bb5, threatening to double Black's pawns with Bxc6, or the more aggressive 5.Bc4, aiming for a kingside attack.

 

Smith–Morra Gambit: 2.d4 

2.d4 cxd4 3.c3 is the Smith–Morra Gambit. Declining it by either 3...Nf6 or 3...d5, transposing to the c3 line, is possible, but accepting it by 3...dxc3 is critical. After 4.Nxc3, White is considered not to have enough compensation for the pawn;however, it can be dangerous for Black if he is unprepared, as there are many pitfalls for the unwary.

 

Other moves

Other reasonable moves include:

• 2.Ne2 is the Keres Variation, a favourite of Paul Keres, and has similar ideas to the Chameleon System discussed under 2.Nc3 – White can follow up with 3.d4 with an Open Sicilian, 3.g3 with a Closed Sicilian, or 3.Nbc3, continuing to defer the choice between the two.

 

• 2.g3, the Steinitz Variation or Lasker-Dunne Attack, was sometimes played by Taimanov. It can transpose to the Closed Sicilian but offers other options such as 2...d5 3.exd5 Qxd5, with Black's queen threatening to capture White's exposed rook, and an incipient central buildup with c3 and d4 for White.

 

 

• 2.c4, the Staunton-Cochrane Variation, occasionally leads to positions that resemble lines in the English Opening. Palliser and Keres recommend avoiding mainline English theory with 2...Nc6 3.Nc3 e5!, which prevents White from playing d4.

• 2.d3 signals White's intention to develop along King's Indian Attack lines, and usually transposes to the Closed Sicilian.

• 2.e5, which gains space and prevents Black playing ...Nf6. White often support the e5-pawn with 3.f4 or 3.Nf3. The drawback of 2.e5 is that no additional pressure is brought to the centre, allowing Black various options. Wilhelm Steinitz played 2.e5 at least three times in tournament play, defeating Szymon Winawer, Max Weiss, and Celso Golmayo Zúpide.

 

• 2.Na3, the Kronberger Variation, is an eccentric move recently returned to prominence by GM Vadim Zvjaginsev at the 2005 Russian Chess Championship Superfinal. He used it thrice during the tournament, drawing twice and beating Alexander Khalifman.

• 2.Qh5, threatening the c-pawn as in the Wayward Queen Attack, was played twice in 2005 by Hikaru Nakamura, but the move is considered dubious. Simply 2...Nf6 gives Black a comfortable position after 3.Qxc5 Nxe4, while 3.Qh4 displaces the queen and loses time. Nakamura lost in 23 moves to Andrei Volokitin in 2005, and Neil McDonald criticised the opening experiment as "rather foolish".

• 2.a4 is usually followed up with 3.f4, with play similar to a Grand Prix Attack. Simon Williams once defeated Jovica Radovanovic with the line.
  
  
  
  
  
• 2.a3, the Mengarini Variation, is similar to the Wing Gambit, the idea being to play 3.b4 next move.

 

 

• 2.b3 followed by 3.Bb2 is the Snyder Variation, named for USCF master Robert M. Snyder.^[58] It has been used occasionally by Nigel Short and is a favourite of Georgian GM Tamaz Gelashvili.

• 2.Bc4 is the Bowdler Attack, and though once played at the highest level, is popular today only among club players or beginners who are unfamiliar with the Sicilian and are looking either to attack the weak f7 pawn or to prepare for a quick kingside castle. However, after a move such as 2...e6, Black will soon play ...d5 and open up the centre while gaining time by attacking the bishop. Anderssen–Wyvill, London 1851 continued 2...e6 3.Nc3 a6 4.a4 Nc6 5.d3 g6 6.Nge2 Bg7 7.0-0 Nge7 8.f4 0-0 9.Bd2 d5 10.Bb3 Nd4 11.Nxd4, and now Soltis recommends 11...cxd4! 12.Ne2 Bd7!

 

• 2.b4 is the Wing Gambit. White's idea is 2.b4 cxb4 3.a3, hoping to deflect Black's c-pawn, then dominate the centre with an early d4. However, Black can gain an advantage with accurate play. The Wing Gambit is thus generally considered too reckless. GM Joe Gallagher calls it "a forgotten relic, hardly having set foot in a tournament hall since the days of Frank Marshall and Rudolph Spielmann. White sacrifices a pawn for ... well, not a lot."

 

Nice

The OP did a great job with his post.

It looks like he quit coming before seeing anyone thank him.

https://en.wikipedia.org/wiki/Sicilian_Defence#

The OP practically copied the entire Wikipedia page on the Sicilian defense word-for-word. Plagiarism shouldn't be celebrated or appreciated.