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

Sicilian Defence
a b c d e f g h
8 a8 b8 c8 d8 e8 f8 g8 h8 8
7 a7 b7 c7 d7 e7 f7 g7 h7 7
6 a6 b6 c6 d6 e6 f6 g6 h6 6
5 a5 b5 c5 d5 e5 f5 g5 h5 5
4 a4 b4 c4 d4 e4 f4 g4 h4 4
3 a3 b3 c3 d3 e3 f3 g3 h3 3
2 a2 b2 c2 d2 e2 f2 g2 h2 2
1 a1 b1 c1 d1 e1 f1 g1 h1 1
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Position in Forsyth-Edwards Notation (FEN)
Moves: 1. e4 c5
ECO code: B20-B99
Parent: King's Pawn Opening

Sicilian DefenceEdit

The moves 1. e4 c5 constitute the Sicilian Defence, a counter-attacking opening in which players typically attack on opposite sides of the board. The Sicilian was introduced to the chess world in 1594 by Giulio Cesare Polerio and emerged into the mainstream in the early 20th century as a somewhat tame variation. 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.

Black's move 1...c5 seeks to create a half-open file, controls the important d4 square, and allows the black queen to venture out if desired, while the c-pawn itself is safe from attack, unlike the e-pawn after 1. e4 e5.

White's responsesEdit

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. c4   (Staunton–Cochrane variation)

1...c5 introduces an element of asymmetry into the position; if White were to respond with 2. c4 (the English-like Staunton–Cochrane variation) imitating Black's move, that would weaken the d4 square and make it more difficult to play d4 later on.

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. d4   (Smith–Morra Gambit)

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. d4 cxd4 3. c3   (Smith–Morra Gambit)

Faced with a pawn on c5, White may choose to play 2. d4 (Smith–Morra Gambit) anyway which typically leads to a pawn sacrifice for quick development. After 2...cxd4, White can play 3. c3, sacrificing another pawn in order to play 4. Nxc3 to gain an advance in development in the Morra Gambit.

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. Nf3   (Open Sicilian)

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. c3   (Alapin variation)

A more common idea is for White to postpone d4 for a move while they increase their own control of the square. This can be achieved by either 2. Nf3 leading to the main lines of the (Open) Sicilian or by 2. c3 attempting to establish a strong pawn centre.

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. b4   (Sicilian Wing Gambit)

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. a3   (Mengarini/Van Duijn variation)

Much less common is the attempt to undermine the c-pawn's control of d4 by playing 2. b4 (Wing Gambit) to tempt it off-centre. Since it is considered safe for Black to take the offered pawn and hold on to it, a more recent idea has been to prepare the b4 move with 2. a3 (Mengarini variation).

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. e5

White can also push the e-pawn again with 2. e5 in an attempt to give Black a cramped position.

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. Nc3   (Closed Sicilian)

 a b c d e f g h  
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
 a b c d e f g h  
2. f4   (Grand Prix/McDonnell Attack)

White may postpone the fight for d4, typically with 2. Nc3 (Closed Sicilian) though 2. f4 (Grand Prix Attack) is also played. 2. f4 is a violent attacking move, 2. Nc3 typically leads to a closed position although f4 can appear later.

StatisticsEdit

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 tableEdit

1. e4 c5

  2 3 4 5 Evaluation Notes
Open Sicilian Nf3
Nc6
d4
cxd4
Nxd4
 
2. Nf3 Nc6 is the Old Sicilian. Leads to Open Sicilian variations such as the Kalashnikov, Sveshnikov, or Accelerated Dragon; or the potentially Closed Sicilian variation the Rossolimo.
Open Sicilian Nf3
d6
d4
cxd4
Nxd4
Nf6
Nc3
 
= 2. Nf3 d6 goes into the modern Sicilian variations. Open Sicilian variations include the Najdorf, Dragon, Classical, and Scheveningen. The Moscow variation is potentially an Open or Closed 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
 
Grand Prix 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
 
Steinitz Variation g3
d5
exd5
Qxd5
Wing Gambit b4
 
Less common
Mengarini Variation a3
 
Less common. Also known as Van Duijn’s variation.
e5
 
Less common
Kronberg Variation Na3
 
Less common.
Qh5
 
Less common. See also: Parham Attack
King David's Opening Ke2
 
Less common.
Sicilian Amazon Attack Qg4
 
Less common.

For explanation of theory tables, see theory table and for notation, see algebraic notation.

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ReferencesEdit

  • Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.


External linksEdit