Chess Opening Theory/1. e4/1...c5

Sicilian defence B20-B99 King's pawn opening 2. Nf3 - Open Sicilian 2. Nc3 - Closed Sicilian 2. c3 - Alapin Variation 2. d4 - Smith-Morra Gambit 2. Bc4 - Bowdler Attack 2. f4 - MacDonnell Attack 2. d3 2. b3 - Snyder Variation 2. c4 - Staunton-Cochrane Variation 2. Ne2 - Keres Variation 2. g3 - Lasker-Dunne Attack 2. b4 - Wing Gambit 2. a3 - Mengarini Variation 2. Be2 - Slow Variation 2. e5?! - Pawn-Push Variation 2. Bd3 - Kopec System 2. Qg4? - Amazon Attack 2. Nh3? - Brick Variation 2. Na3? - Zvjaginsev Variation 2. g4? - Grob Variation 2. a4? - Myers Attack, with a4 2. h4? - Myers Attack, with h4 2. Ke2? - King David's Opening 1...c5 · Sicilian defence 1...c5 is the Sicilian defence, a counter-attacking, asymmetric opening. Black controls the d4 square with a flank pawn, asserting that trading their flank c-pawn for White's d-pawn will surely be to their advantage, as it will leave them with two central pawns to White's one. Black would love to one day achieve d5, and exploit the c-file should it open. The main approach for White is the Open Sicilian: 2. Nf3 intending to bust open the position with 3. d4. This is the most testing approach, but as it is also normally what Black is most prepared for, a number of other approaches, the "anti-Sicilians", are also popular. Open the position The drawback of 1...c5 is that it does not help Black to develop (compare 1...e5, which both controls d4 and opens a line for the king's bishop). After 1...c5, Black must eventually play another pawn move before a bishop can come out. Therefore White will be able to develop faster, and the most principled way to press this advantage is to open the position. 2. Nf3 is the Open Sicilian. This prepares 3. d4 cxd4 and White can recapture with the knight. They will have a centralised knight, clear lines to develop both bishops and their queen, and an open, attacking position. Black has a centre pawn majority and a half-open c-file. After the moves 2...Nc6 or 2...d6, White has the alternative 3. Bb5, the Rossolimo or Moscow variations respectively. White can also play 2. d4 immediately, without preparing it with 2. Nf3. This was the approach in the 19th century25-28 but after 2...cxd4 3. Qxd4!? loses time to 3...Nc6, so today it is more usual to prepare d4 with 2. Nf3. Alternatively White may play 2. d4 cxd4 3. c3, the Smith-Morra gambit, to offer a pawn in exchange for faster development. Keep the position closed 2. Nc3 is the chief alternative second move. White opts to avoid trading their d-pawn and keep the position closed. In the mainline Closed Sicilian, White fianchettos their kingside bishop and plays d3, Be3, Nge2, and Qd2. This typically leads to a more closed and slow-burning position. Another approach for White is to take advantage of their space on the kingside and launch the violent Grand Prix attack, where White plays an early f4, places their knight on f3 behind the pawn, and brings their queen into the attack via a Qd1-Qe1-Qh4 manoeuvre. 2. Nc3 is also a waiting move: after they get a bit more information about how Black wishes to play, White may still play Nf3 and d4 and transpose. Play d4 and keep it there White may wish to put a pawn on d4 and have some hope of keeping it there. 2. c3, the Alapin, prepares to play 3. d4 and if the d-pawn is captured, to replace it with the c-pawn. This diffuses any advantage Black would hope to gain from trading a flank pawn for a centre pawn as White keeps two pawns in the centre. Black can't prevent White from playing 3. d4 but they can at least ensure that White does not get to keep a big, classical centre with both d- and e-pawns side-by-side. The main moves are 2...Nf6, inducing 3. e5 Nd5 4. d4, or 2...d5, taking advantage of the fact that after 3. exd5 Qxd5 White's c3 pawn prevents Nc3 to kick the queen. Alternatively, White can try to reduce Black's control of the d4 square, then play d4. If White likes Black's idea of trading a more peripheral pawn for a less peripheral pawn, they can try to trade their b-pawn for Black's c-pawn. 2. b4, the Wing Gambit, tempts Black's c5 pawn away from controlling d4: after 2...cxb4 White can happily play d4 and achieve a two pawn centre. White solved one problem but now must contend with another: how to develop their knight, whose normal space c3 is now controlled by Black's pawn. A more recent idea is 2. a3, the Mengarini variation, preparing 3. b4: after 2...Nc6 3. b4 cxb4 4. axb4 Nxb4 5. d4 White gets two pawns in the centre and no obstacle to developing their knight. If Black is less accommodating however, they will not take: 2...g6 3. b4 Bg7 (threatening Bxa1) 4. Nc3 d6 is the mainline. Other moves 2. f4, the MacDonnell attack, a violent attacking move like an accelerated Grand Prix attack. However, since White hasn't played Nc3 yet to control d5, Black has the option of 2...d5!, the Tal gambit. 2. f4 was the approach taken by MacDonnell against La Bourdonnais in 1834. The more usual approach to the Grand Prix today is to begin with 2. Nc3. 2. c4 is the Staunton-Cochrane variation. White locks down on the d5 square to prevent the freeing move ...d5 (a Maróczy bind), however the pawn move is committal and White has permanently weakened the d3 and d4 squares. This can transpose into a Botvinnik system otherwise seen in the Symmetrical English (where White puts pawns on c4, d3, e4, and g3 and plays Nc3, Ne3, and Bg2). 2. Bc4 is the Bowdler attack. The c4 square is less optimal for the bishop in this position than after 1. e4 e5 as Black is able to play 2...e6 to end its pressure on f7. ...d5 will soon follow and Black is thought to have the edge. 2. Ne2 is the Keres variation, a modest developing move which keeps White's options open. This is very transpositional; it is also played in the order 2. Nc3 & 3. Ne2 where it is called the Chameleon. White can later play d4 & Nxd4 to open up the position, by which time they may have move-ordered Black out of the Sicilian they usually play, or they can play a Closed Sicilian with g3 and Bg2. 2. Be2, known as the Slow variationSicilian Defense: Slow Variation - Chess Openings https://www.chess.com/openings/Sicilian-Defense-Slow-Variation 2026-03-29 Chess.com en-US, can lead to positions where White plays in a compact, defensive way, prioritising castling before making any commitments on the queenside. White keeps the position closed, plays an early f4, Nf3, and castles. Not having played Nc3 yet they may play Nd2 and c3. 2. g3, preparing the fianchetto, is the Lasker–Dunne attack. This can transpose into a Closed Sicilian or White can combine it with c3 and d4. However this does allow Black the sequence 2...d5 3. exd5 Qxd5 (threatening Qxh8) 4. Nf3 to open the position. 2. e5?!, the so-called Pawn-push variation, seeks to take advantage of the fact that Black hasn't played ...e5. From e5, White's pawn will cramp Black's position and hamper development of their king's knight. However, Black can usually end up winning the pawn or trading it for development. Black is better after 2...Nc6 (attacking pawn and controlling d4) 3. Nf3 (defending pawn) Qc7 (attacking pawn) 4. Qe2 (defending pawn) f6! 5. exf6 Nxf6. 2. Bd3 is the Kopec System, named after IM Danny KopecList of chess openings named after people 2026-02-08 https://en.wikipedia.org/w/index.php?title=List_of_chess_openings_named_after_people&oldid=1337248305 Wikipedia 2026-03-29 enDanny Kopec 2025-12-17 https://en.wikipedia.org/w/index.php?title=Danny_Kopec&oldid=1328069748 Wikipedia 2026-03-29 en 2. Na3, utilised by GM Vadim Zvaginsev in the 2005 Russian Championship Superfinal, defeating Alexander Khalifman. Also known as the Kronberger Variation Bad moves 2. Nh3? is known as the Brick variation 2. g4? is known as the Grob variationSicilian Defense: Grob Variation - Chess Openings https://www.chess.com/openings/Sicilian-Defense-Grob-Variation 2026-03-29 Chess.com en-US 2. a4? and 2. h4? are each known as the Myers attackSicilian Defense: Myers Attack, with a4 https://lichess.org/opening/Sicilian_Defense_Myers_Attack_with_a4/e4_c5_a4 2026-03-29 lichess.org en-USSicilian Defense: Myers Attack, with h4 https://lichess.org/opening/Sicilian_Defense_Myers_Attack_with_h4/e4_c5_h4 2026-03-29 lichess.org en-US 2. Qg4? is the delirious Amazon attack. White develops their queen out of order, only to allow Black to play ...Nf6 with tempo. 2. Ke2? is the second worst possible move in the position (after 2. Ba6??). Though never played seriously it has for whatever reason a name, King David's opening, perhaps to evoke David sallying forth to battle Goliath in single combat and reminiscent of the Bongcloud opening. History The earliest analysis of 1...c5 comes from a 1594 codex by Giulio Polerio l'Apruzzese (c. 1555-1610). It was analysed by Pietro Carrera in his 1617 work Il Gioco degli Scacchi (The Game of Chess). Carrera was born in Sicily so it is believed to be for him that the name Sicilian defence was adopted.Winning With the Sicilian Taimanov Mark Collier Books, Macmillan Publishing Company 1991 0 02 029864 1 New York English translated from Russian It was not originally considered to be a good opening for Black until it was used by La Bourdonnais in his 1834 match series against Alexander MacDonnell, a precursor to the modern world chess championship. La Bourdonnais's success led to a critical reappraisal: a few years later in 1842, Jaenisch wrote that 1...c5 was the best reply to 1. e4.Jaenisch's chess preceptor: a new analysis of the openings of games de Jaenisch C. F. Longman & co. 1847 London https://babel.hathitrust.org/cgi/pt?id=hvd.hn52dv&seq=5 Walker George (translation of Analyse nouvelle des ouvertures du jeu des échecs de Jaenisch C. F. Gartner 1842)25-28 Anderssen (1818―1879) and Paulsen (1833-1891) made major contributions to the theory in the 19th century, and by the early 20th century the Sicilian had entered the mainstream. With the discovery of new attacking ideas, it became Black's most feared weapon by the 1950s and is, pound for pound, the most exhaustively analysed of all openings. Statistics Databases give White approximately 36% winning chances, drawing is at 30%, and Black wins 33%. Estimated next move popularity: Nf3 74%, Nc3 10%, c3 7%, d4 3%, Bc4 2%, f4 2%, d3 1%, b3 1%, c4 1%, Ne2 1%, g3 0.4%, b4 0.4%, other moves less than 0.3%. Note that these move frequencies are biased toward databases of stronger players. The next move frequency may be very different for club players. For instance, see the data from the Lichess database below where 2. Nf3 occurs less commonly at only 56% of the time while 2. Bc4 occurs as often as 7% of the time. move average 365Chess.com (big) Chess Tempo (all) chessgames.com Lichess (masters) Lichess (database) 2. Nf3 74.2% 75.4 76.4 80.8 82.2 56.0 2. Nc3 9.5 10.5 10.4 8.4 7.6 10.8 2. c3 6.6 7.6 7.2 6.1 6.6 5.4 2. d4 2.6 1.6 1.5 1.0 0.5 8.1 2. Bc4 1.6 0.4 0.3 0.1 0.0 7.3 2. f4 1.5 1.0 0.8 0.7 0.5 4.5 2. d3 1.0 0.8 0.7 0.6 0.6 2.2 2. b3 0.6 0.6 0.7 0.6 0.5 0.5 2. c4 0.6 0.6 0.5 0.3 0.2 1.2 2. Ne2 0.5 0.5 0.6 0.6 0.5 0.3 2. g3 0.4 0.4 0.4 0.3 0.3 0.6 2. b4 0.4 0.3 0.3 0.2 0.1 1.0 everything else 0.6 0.0 0.0 0.0 0.0 0.3 Theory table 1. e4 c5   2 3 4 5 Evaluation Notes Open Sicilian Nf3 Nc6 d4 cxd4 Nxd4   2. Nf3 Nc6 is the old form of the Sicilian. It leads to Open Sicilians such as the Kalashnikov, Sveshnikov, or Accelerated Dragon. If White does not wish to enter an Open Sicilian, they may play a Rossolimo Open Sicilian Nf3 d6 d4 cxd4 Nxd4 Nf6 Nc3   = 2. Nf3 d6 goes into the modern Open Sicilian variations. These include the Najdorf, Dragon, Classical, and Scheveningen, among others. The Moscow is an alternative for those who do not want an Open Sicilian. Closed Sicilian Nc3 Nc6 g3 g6 Bg2 Bg7 d3 d6 = Alapin Variation c3 Nf6 e5 Nd5 d4 cxd4 Nf3 Nc6 = Smith–Morra Gambit d4 cxd4 c3 dxc3 Nxc3 Nc6 Nf3 d6 = Bowdler Attack Bc4   MacDonnell Attack f4 d5 Nc3 d4 Nce2 Nc6 d3 c4 = d3 d3   Often a Closed Sicilian, but a King's Indian Attack is also possible. Snyder Variation b3 Nc6 Bb2   Staunton–Cochrane Variation c4 Nc6 Nc3 g6 = Keres Variation Ne2 Nc6 Nbc3   Lasker-Dunne Attackg3   Steinitz Variation g3 d5 exd5 Qxd5 Wing Gambit b4   Less common Mengarini Variation a3   Less common. Also known as Van Duijn’s variation.Slow VariationBe2  Less common Pawn Push Variation e5   Less commonKopec SystemBd3  Named after IM Danny Kopec Amazon Attack Qg4   Less common.Brick VariationNh3  Less commonSicilian Defense: Brick Variation https://lichess.org/opening/Sicilian_Defense_Brick_Variation/e4_c5_Nh3 2026-03-29 lichess.org en-US Zvjaginsev Variation Na3  Utilised by GM Vadim ZvaginsevList of chess openings named after people 2026-02-08 https://en.wikipedia.org/w/index.php?title=List_of_chess_openings_named_after_people&oldid=1337248305 Wikipedia 2026-03-29 en in the 2005 Russian Championship SuperfinalSicilian Defence 2026-03-29 https://en.wikipedia.org/w/index.php?title=Sicilian_Defence&oldid=1345973671 Wikipedia 2026-03-29 enVadim Zvjaginsev vs Alexander Khalifman (2005) https://www.chessgames.com/perl/chessgame?gid=1379718 2026-03-29 www.chessgames.com, defeating Alexander Khalifman. Also known as the Kronberger VariationSicilian Defense: Kronberger Variation https://lichess.org/opening/Sicilian_Defense_Kronberger_Variation/e4_c5_Na3 2026-03-29 lichess.org en-USGrob Variationg4  See also: Grob's Attack Qh5   Less common. Played twice in 2005 by Hikaru Nakamura, but the move is considered dubious. See also: Parham AttackMyers Attack, with a4a4  Less common. Named after NM Hugh Myers, known for his writings on unorthodox openingsHugh Myers 2025-05-05 https://en.wikipedia.org/w/index.php?title=Hugh_Myers&oldid=1288982613 Wikipedia 2026-03-29 en.Myers Attack, with h4h4  Less common. Named after NM Hugh Myers, known for his writings on unorthodox openingsHugh Myers 2025-05-05 https://en.wikipedia.org/w/index.php?title=Hugh_Myers&oldid=1288982613 Wikipedia 2026-03-29 en. King David's Opening Ke2   Less common. See also: The Bongcloud References See also Sicilian Defence External links 365Chess: 1. e4 c5 fi:Shakkiaapinen/Peli/1. e4/1...c5