Chess Opening Theory/1. c4

__NOTOC__ English Opening rd nd bd qd kd bd nd rd pd pd pd pd pd pd pd pd pl pl pl pl pl pl pl pl rl nl bl ql kl bl nl rl 1. c4 A10-A39 Starting position 1. c4 · English Opening 1. c4 is the English Opening. It is the fourth most commonly played opening move in chess. By playing this move, White allows the queen to move freely and also discourages Black from responding with 1...d5. Additionally, White ensures that the c-pawn will not be blocked behind a knight on c3. The resulting positions often resemble those that arise from 1. d4 openings rather than 1. e4 openings, and the move d4 is frequently played later on. While this opening is not as sharp as 1. e4 or 1. d4, it is still effective in controlling the d5 square and is highly flexible, allowing for easy transpositions into other openings, and is often used when White desires to avoid certain responses to 1. d4 by Black. For example, transposition to Queen's Gambit and Indian Defence positions are very frequently seen. Black's responses /1...Nf6/ is likely to transpose into an Indian Defence or one of the alternative lines below. /1...e5/ is a reversed Sicilian Defence, but the extra tempo for White changes the patterns noticeably. /1...e6/ prepares 2...d5 and is known as the Agincourt Defense. It often ends up transposing to a Queen's Gambit Declined or Indian Defence. An independent alternative line is the Mikėnas-Carls Variation, continuing 2. Nc3 Nf6 3. e4. /1...c5/ is the Symmetrical Variation, which has many unique lines. Often a d4 or d5 pawn break will occur later in the game. /1...c6/ will usually either transpose into the Caro-Kann Defence or the Slav Defence. /1...f5/, the Anglo-Dutch Defence, leads to sharp tactical lines for Black, but can open a powerful kingside attack. This is likely to transpose into the regular Dutch Defense after 2.d4. /1...g6/ is likely to transpose into a King's Indian Defence, Reversed Sicilian, or Symmetrical Variation. /1...b6/ will in all likelihood transpose into the English Defence. /1...d5/ is seldom played but may transpose into the Queen's Gambit or the Réti Opening. /1...b5/, the Jaenisch or Halibut Gambit, can give good practical chances for Black, but is considered unsound at the professional level. /1...g5/, the Myers Defence, gives White a small advantage. 1...Nc6, the Anglo-Lithuanian Variation, is relatively rare, with 2. Nc3 or 2. g3 staying in the realm of English openings and 2. d4 transposing into a line in the Mikenas Defence. Statistics move average 365Chess.com (big) Chess Tempo (all) chessgames.com Lichess (masters) Lichess (database) ...Nf6 28.2% 30.9 30.3 31.4 28.4 20.0 ...e5 23.2 22.6 23.0 22.0 24.0 24.6 ...e6 13.4 13.2 13.4 14.4 14.4 11.7 ...c5 11.7 11.8 11.9 11.4 11.5 12.0 ...g6 7.7 8.0 7.6 8.4 8.2 6.6 ...c6 7.4 6.9 7.4 7.1 8.3 7.0 ...f5 2.8 3.5 3.1 2.9 2.5 2.0 ...b6 1.7 1.5 1.6 1.4 1.6 2.3 ...d5 1.6 0.2 0.2 0.1 0.0 7.7 ...d6 1.4 1.0 0.9 0.6 0.7 3.8 ...Nc6 0.5 0.4 0.4 0.3 0.3 1.1 ...b5 0.1 0.0 0.0 0.1 0.0 0.5 ...a6 0.1 0.0 0.0 0.0 0.0 0.2 ...g5 0.0 0.0 0.1 0.0 0.0 0.1 everything else 0.1 0.0 0.0 0.0 0.0 0.5 Theory table 1.c4 1 2 3 4 5 6 Symmetrical Variation c4c5 Nf3Nf6 g3b6 Bg2Bb7 O-Og6 = Reversed Sicilian Defence ...e5 Nc3Nc6 Nf3Nf6 g3d5 cxd5Nxd5 ∞ Agincourt Defence ...e6 Nc3Bb4 Qb3Nc6 Nf3Nf6 a3Bxc3 ∞ Anglo-Slav Variation ...c6 Nf3d5 g3Nf6 Bg2dxc4 O-ONbd7 ∞ Anglo-Indian Defence ...Nf6 Nc3e6 e4c5 e5Ng8 Nf3Nc6 ∞ Great Snake Variation ...g6 e4e5 d4Nf6 dxe5Nxe4 Bd3Nc5 ∞ English Defence ...b6 d4e6 e4Bb7 ∞ Anglo-Dutch Defence ...f5 Nf3Nf6 g3g6 Bg2Bg7 O-OO-O ∞ Anglo-Scandinavian Defence ...d5 cxd5Qxd5 Nc3Qa5 += Anglo-Lithuanian Variation... Nc6∞ Myers Defence ...g5 d4Bg7?! Bxg5!c5 Nf3cxd4 Nxd4Qb6 Nb5Bxb2?! +- Halibut Gambit ...b5 cxb5a6 e4!Bb7 Nc3Nf6 e5Nd5 Nf3e6 += All possible Black's moves QuickNavigationNa6a6a5b6b5Nc6c6c5d6d5e6e5Nf6f6f5g6g5Nh6h6h5 References English Opening fi:Shakkiaapinen/Peli/1. c4