Chess Opening Theory/1. d4/1...Nf6/2. c4

Indian defence Indian defence 2. c4 White takes more space and increases the control of the important d5 square. This move order allows White's queenside knight to develop to the active c3 square without blocking the c-pawn. Black has a range of different responses and two main plans: contest White's centre immediately with pawns in the classical way, or focus on development and open lines for their bishops, in the hypermodern way. Contest the centre with pawns Capablanca warns us that "two or more pawns are strongest when they are in the same rank next to one another."Chess Fundamentals Capablanca José Raúl Harcourt, Brace and Company 1921 New York 6.31. Some salient points about pawns. Therefore Black may wish to assault White's pawn centre to force some weaknesses. 2...c5 is the Benoni defence. In theory this is a pawn sacrifice. If White were to play 3. dxc5?!, Black would be very happy to play 3...e6! (preparing to recapture the pawn; the Weenink variation). Therefore White prefers to keep their d-pawn in the centre with 3. d5. Even though Black cannot remove the d-pawn in this way, at least by forcing it to advance to the next rank, they have weakened the White's grip. After 3. d5 Black tries to attack the pawn chain and play on the queenside. The main continuations are 3...e6, the Modern Benoni (often aggressive, risky), or 3...b5, the Benko gambit (positional pawn sacrifice by Black on the queenside). 2...e5 is the Budapest defence. It has a unique character and often allows Black active play. It offers the e5 pawn with tempo on the knight, 3. dxe5 Ng4, but White usually gives the pawn back eventually. White usually gets a slightly better position, but Black can do well against an unprepared opponent. Black can't transpose into a Queen's gambit declined right now. 2...d5 is the Marshall defence. This allows 3. cxd5 Nxd5 4. e4 Nf6+, and White gets a big centre and the advantage. Prepare to develop a bishop In order to develop their pieces, Black will have to first choose a pawn move to free one of their bishops. Typically the approaches are to free the bishops with ...d6 and ...g6 (what Tartakower called "Old Indian defences") or ...e6 and ...b6 (what Tartakower called the "Neo-Indian defences"). 2...e6 is the most common move. It is solid and flexible, and prepares to develop the kingside bishop along the a3-f8 diagonal. It also gives Black the option to transpose into a Queen's gambit declined with ...d5. Depending on how White plays and Black responds, this can lead a Queen's Indian defence with ...b6, Nimzo-Indian, Bogo-Indian, Benoni, or a Catalan games. 2...b6 is the Accelerated Queen's Indian. Black prepares to fianchetto their queenside bishop. It is "accelerated" as the Queen's Indian is usually reached through the move order 2...e6 3. Nf3 b6. 2...g6, sometimes called the West Indian, prepares to fianchetto the kingside bishop. This tends to be a more combative approach. This typically leads to a King's Indian defence, or a Grünfeld after 3. Nc3 d5. 2...d6 is called the Old Indian. This opens the c8-h3 diagonal for the bishop, but Black often develops his knight to d7 first. This can transpose into the King's Indian defence (e.g. 3. Nc3 g6 4. e4 Bg7), but there are lines with their own flavour where Black plays ...e5, ...Be7, and ...O-O. Other moves 2...c6 is the rare Slav Indian, looking for a transposition to the Slav Defence. White typically allows this with 3. Nc3 or 3. Nf3, but can refuse with 3. Bf4. 2...Nc6 is the Mexican defence or Black knights tango. Though the knight can be kicked immediately with 3. d5, it safely relocates to 3...Ne5. The mainline goes 3. Nf3 (preventing ...e5) e6 4. Nc3 Bb4. 2...b5!? is a rare response named the Pyrenees Gambit, a dubious wing gambit with the aim of deflecting the c-pawn away from controlling the center. 2...g5? is a rare, unsound and bad response, gambitting the g5 pawn to 3. Bxg5, named the Medusa Gambit. Theory table . 1. d4 Nf6 2. c4 2 3 4 5 6 King's Indian Defence c4g6 Nc3Bg7 e4d6 Nf3O-O Be2e5 = Grunfeld Defence ...... ...d5 cxd5Nxd5 e4Nxc3 bxc3Bg7 = Benoni Defence ...c5 d5e6 Nc3exd5 cxd5d6 e4g6 +/= Queen's Indian Defence ...e6 Nf3b6 a3Bb7 Nc3d5 cxd5Nxd5 +/= Bogo-Indian Defence ...... ...Bb4+ Bd2Qe7 g3Nc6 Nc3Bxc3 +/= Nimzo-Indian Defence ...... Nc3Bb4 e3O-O Bd3d5 Nf3c5 = Catalan Opening ...... g3d5 Bg2dxc4 Nf3Be7 O-OO-O = Black Knights' Tango ...Nc6 Nf3e6 a3d6 Nc3g6 e4Bg7 +/= Budapest Gambit ...e5 dxe5Ng4 Bf4Nc6 Nf3Bb4+ Nbd2Qe7 += Old Indian Defence ...d6 Nc3e5 Nf3Nbd7 e4Be7 +/= Marshall Defence ...d5 cxd5Nxd5 Nf3Bf5 Qb3 +/= References See also Indian Defence fi:Shakkiaapinen/Peli/1. d4/1...Rf6/2. c4