The Sicilian Defence is a chess opening that begins with the following moves: 1. e4 c5

1...c5 is one of the most popular responses to White's first move 1.e4. Like 1...e5, the move contests control of the d4-square, but breaks symmetry immediately, often leading to and positions.

The earliest recorded notes on the Sicilian Defence date back to the late 16th century by the Italian chess players Giulio Polerio and Gioachino Greco. It was extremely popular in the second half of the 20th century and was extensively played and analysed by many grandmasters, such as Bobby Fischer, Garry Kasparov, and Mikhail Tal.

General concepts By advancing the c-pawn two squares, Black asserts control over the d4-square and begins the fight for the . The move resembles 1...e5, the next most common response to 1.e4, in that respect. Unlike 1...e5, however, 1...c5 breaks the of the position, which strongly influences both players' future actions. White, having pushed a pawn, tends to hold the initiative on that side of the board. However, 1...c5 does little for Black's , 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 pawn has given Black a 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 . The pawn trade also opens the c- for Black, who can place a rook or queen on that file to support the queenside . In many variations, White castles queenside to exploit attacking chances on the kingside at the cost of moving his king to the flank where Black has a spatial advantage.

History Early history The Sicilian Defence was analysed by Giulio Polerio in his 1594 manuscript on chess, though he did not use the term 'Sicilian Defence'. It was later the subject of analyses by leading players of the day Alessandro Salvio (1604), Don Pietro Carrera (c. 1617), and Gioachino Greco (1623), and later Conte Carlo Francesco Cozio (c. 1740). The great French player and theoretician André Danican Philidor opined of the Sicilian in 1777, "This way of opening the game ... is absolutely defensive, and very far from being the best ... but it is a very good one to try the strength of an adversary with whose skill you are unacquainted."

19th century In 1813, the English master Jacob Henry Sarratt effectively standardised his English translation of the name of this opening as 'the Sicilian Defence', referring to an old Italian manuscript that used the phrase ('the Sicilian game'). The Sicilian was fairly popular for much of the nineteenth century; Louis-Charles Mahé de La Bourdonnais, Adolf Anderssen, Howard Staunton, Louis Paulsen, and Carl Jaenisch all played it with some consistency. In the ninth edition of Modern Chess Openings, Walter Korn noted that the Sicilian "received three of its earliest practical tests, and a big boost in popularity, in the 1834 La Bourdonnais–McDonnell chess matches, 1843 Staunton–St. Amant match, and the London 1851 chess tournament." Staunton wrote of the Sicilian, "In the opinion of Jaenisch and the German Handbuch, with which I coincide, this is the best possible reply to 1.P-K4, [1.e4 in algebraic notation] 'as it renders the formation of a centre impracticable for White and prevents every attack'." Modern players would consider the notion that the Sicilian "prevents every attack" naive.

The opening fell out of favour in the later part of the nineteenth century, when some of the world's leading players rejected it.Henry Bird, writing in 1883, summarized the fluctuations in the Sicilian's reputation thus:The Sicilian ... has probably undergone more vicissitudes in regard to its estimation and appreciation than any other form of defence. In 1851, when the Great Exhibition London Tournament was commenced, it was entirely out of favour, but its successful adoption on so many occasions by Anderssen, the first prize winner, entirely restored it to confidence; however, its rejection by Morphy in 1857–8, and by Steinitz in 1862, caused it again to lapse in consideration as not being a perfectly valid and reliable defence. Its fortunes have since continued in an unsettled state. Staunton (three weeks before his death), ... pronounced it to be quite trustworthy, and on the same date Lowenthal expressed a similar opinion. Baron Kolisch ... concurs in these views. Paul Morphy, the world's best player in the late 1850s, decried "that pernicious fondness for the Sicilian Defense ... extending from about 1843 to some time after 1851". Wilhelm Steinitz, the first World Champion, also disliked the Sicilian and rejected it in favour of 1...e5."Steinitz, throughout his life, had a certain dislike of the Sicilian. He never ceased to write that he preferred 1...e5 and the majority of players followed his example." Remarks of Henry Bird, quoted above. The death of the opening's two greatest proponents, Staunton and Anderssen, in 1874 and 1879 respectively, also contributed to its decline. It has been said that "these losses almost dealt a knockout blow to the Sicilian because it took a long time to find such important figures to carry the Sicilian's standard." George H. D. Gossip, in The Chess Player's Manual, first published in 1874, wrote, "Of late years ... discoveries have been made which have the effect of considerably strengthening White's attack, and the 'Sicilian' is now considered by most modern authorities to be a comparatively weak mode of play." Freeborough and Ranken, in their treatise Chess Openings: Ancient and Modern (1889, 1896), wrote that the Sicilian "had at one time the reputation of being the best reply to 1.P-K4 [1. e4], but this has not been confirmed by popular practice. Several eminent players have, however, held to the opinion that it is quite trustworthy."

Early 20th century The Sicilian continued to be shunned by most leading players at the start of the twentieth century, as 1...e5 held centre stage. José Raúl Capablanca, the World Champion from 1921 to 1927, famously denounced it as an opening where "Black's game is full of holes". Similarly, James Mason wrote, "Fairly tried and found wanting, the Sicilian has now scarcely any standing as a first-class defence. ... [It] is too defensive. There are too many holes created in the Pawn line. Command of the field, especially in the centre, is too readily given over to the invading force." Siegbert Tarrasch wrote that 1...c5 "is certainly not strictly correct, for it does nothing toward development and merely attempts to render difficult the building up of a centre by the first player. ... The Sicilian Defence is excellent for a strong player who is prepared to take risks to force a win against an inferior opponent. Against best play, however, it is bound to fail." The Sicilian was not seen even once in the 75 games played at the great St. Petersburg 1914 tournament.The Grand International Masters' Tournament at St. Petersburg 1914, David McKay, c. 1915, p. 75.

Nonetheless, some leading players, such as Emanuel Lasker (World Champion from 1894 to 1921), Frank Marshall, Savielly Tartakower, and Aron Nimzowitsch, and later Max Euwe (World Champion from 1935 to 1937) played the Sicilian. Even Capablanca and Tarrasch, despite their critical comments, occasionally played the opening. It was played six times (out of 110 games) at New York 1924. The following year, the authors of Modern Chess Openings (4th edition) wrote, "The Sicilian has claims to be considered as the best of the irregular defences to 1.P-K4 at Black's disposal, and has been practised with satisfactory results by the leading players of the day." Twelve years earlier, in the second edition, the authors had written, "For many years, the Sicilian has enjoyed a fair, though fluctuating amount of favour for match play. While it is not analytically so sound as the French, it affords greater opportunity for counter attack and less chance of an early draw." In this period Black's approach was usually slow and positional, and the all-out attacks by White that became common after World War II had not yet been developed.

Later 20th century The fortunes of the Sicilian were further revived in the 1940s and 1950s by players such as Mikhail Botvinnik, Isaac Boleslavsky, Alexander Kotov, David Bronstein, and Miguel Najdorf. Reuben Fine, one of the world's leading players during this time period, wrote of the Sicilian in 1948, "Black gives up control of the center, neglects his development, and often submits to horribly cramped positions. How can it be good? Yet, the brilliant wins by White are matched by equally brilliant wins by Black; time and again the Black structure has been able to take everything and come back for more." (described as "an unabridged and unaltered republication" of .

Later, Bent Larsen, Ljubomir Ljubojević, Lev Polugaevsky, Leonid Stein, Mark Taimanov, and Mikhail Tal all made extensive contributions to the theory and practice of the defence. Through the efforts of world champions Bobby Fischer and Garry Kasparov, the Sicilian Defence became recognised as the defence that offered Black the most winning chances against 1.e4. Both players favoured sharp, aggressive play, and employed the Sicilian almost exclusively throughout their careers, burnishing the defence's present reputation. World champion Anatoly Karpov also played the Sicilian quite frequently during his peak-strength period. Today, most leading grandmasters include the Sicilian in their opening repertoire.

In 1990, the authors of Modern Chess Openings (13th edition) noted that "in the twentieth century the Sicilian has become the most played and most analysed opening at both the club and master levels." In 1965, in the tenth edition of that book, grandmaster Larry Evans observed that "The Sicilian is Black's most dynamic, asymmetrical reply to 1.P-K4. It produces the psychological and tension factors which denote the best in modern play and gives notice of a fierce fight on the very first move."

Recent views Grandmaster (GM) John Nunn attributes the Sicilian Defence's long term 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." GM Jonathan Rowson considered why the Sicilian is the most successful response to 1.e4 in 2005, writing:

GM Magnus Carlsen, World Champion for over ten years, is a regular practitioner of the Sicilian.

Overview White's main move is 2.Nf3, usually with the idea of opening the game with 3.d4 cxd4 4.Nxd4; or the positions may remain closed, such as in the Rossolimo Variation (2.Nf3 Nc6 3.Bb5). The main alternatives are 2.Nc3, a developing move leading to the Closed Sicilian or transposing to another line; and 2.c3, the Alapin Variation, aiming to support a later d4. Other possibilities include 2.f4, the Grand Prix Attack, controlling e5 and potentially leading to a kingside attack; or an immediate 2.d4, which may lead to the Smith–Morra Gambit.

Open Sicilian: 2.Nf3 and 3.d4