user-1: What are the main ideas for White after 1. d4 d5 2. c4 dxc4 3. e4?
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4


user-1: Black has 4 main tries and one dubious line. White's plans vary based on the tabiya. The positions below are the lines given in Starting Out: Queen's Gambit Accepted by Reatsky and Chetverik:
3...e5
[FEN ""]
[StartPly "5"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 {Best and thematic. A strong central counterattack that made the 3. e4 QGA unpopular in the '80s.} 4. Nf3 {White defends the pawn and prepares to castle kingside.}

Now Black has 2 choices: 4...Bb4+ and 4...exd4.
4...Bb4+
[FEN ""]
[StartPly "7"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 4. Nf3 Bb4+ {Black develops with tempo and blocks a defender of the d4 pawn.} 5. Bd2 Bxd2+ {Black is happy to trade, seeing as he is up material and has slightly less space when the c4 pawn falls.} 6. Nbxd2 {6. Qxd2 exd4 7. Qxd4 Nf6 8. Qxd8+ Kxd8 actually sucks the venom out of white's attack, as the queens are gone and the trades benefit black, whose king is open and has less space.} exd4 7. Bxc4 Nc6 8. O-O Qf6 {Black aims to play ...Nge7 and ...O-O.} 9. e5 {The queen has developed early and can be attacked, gaining space. The pawn cannot be taken due to tactics on the open e-file.} Qg6 10. Re1 Nge7 11. Nb3 {Thematically regaining the pawn.} O-O 12. Nfxd4 {The material is now even with quite even development and safe kings. But why was it the f3 knight that recaptured? Well: 1) 12...Na5, pestering the bishop, is prevented, and 2) The queen can develop to the kingside, e.g. Qf3 easily.}

4...exd4
[FEN ""]
[StartPly "7"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 4. Nf3 exd4 {Black invites white to play 5. Qxd4? Qxd4 6. Nxd4 Bc5 which equalises. Similarly, 5. Nxd4? c5 6. Nf3 Qxd1+ is also good for black.} 5. Bxc4 {White should definitely develop the bishop to regain a pawn and take control of a key diagonal.} Nc6 6. O-O Be6 {Defending the diagonal leading to the weak f7 square, this almost forces a trade of a well developed piece.} 7. Bxe6 {7. Bb5 is playable. See Kaspaprov-Anand, Linares 1999} fxe6 8. Qb3 Qd7 {Why not 8...Qc8? Well this is too passive and can be punished by 9. Ng5!} 9. Qxb7 Rb8 10. Qa6 Nf6 11. Nbd2 Bd6 {The bishop develops to a flexible square that discourages e5.} 12. Qd3 O-O 13. a3 {Preventing any annoying ...Nb4 or ...Bb4 manoeuvres.} Ng4 {Black seeks to place a knight on e5, a well placed steed.} 14. b3 Nce5 15. Nxe5 Nxe5 16. Qxd4 Ng4 17. e5 Nxe5 18. Bb2 Rb5 19. Qe4 Nd3 20. Bd4 Rf4 21. Qa8+ Rf8 {With a likely draw by threefold repition.}

3...c5
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 c5 4. d5 Nf6 5. Nc3 b5 {Principle: attacked in the centre, counter on the wing} 6. Bf4 {The Bishop thematically comes to f4 as in some variations the bishop takes on b8, often in conjunction with a rook on b1.} Ba6 {Black has to develop rapidly, as the game is somewhat open and Black is being squeezed in the centre.} 7. e5 b4 8. exf6 bxc3 9. bxc3 gxf6 10. Bxc4 {This initiates a combination that simplifies into an endgame where white plays against the pawn weaknesses on c5 and the kingside.} Bxc4 11. Qa4+ Nd7 12. Qxc4 Nb6 13. Qb5+ Qd7 14. Qxd7+ Kxd7

3...Nc6
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 Nc6 4. Nf3 Bg4 5. d5 Ne5 6. Bf4 Ng6 {6...Nxf3 7. gxf3 Bd7 is not so strong for Black, as White now has a semi-open g-file to work with, and the White king is reasonably safe in the centre.} 7. Be3 e5 8. Bxc4 Nf6 9. Nc3 a6 {Black threatens to remove the defender of the e4 pawn with 10...b5 11. Be2 b4 12. Ng1 Nxe4} 10. Be2 {White would like to offer to trade the bad light square bishop with Nd2, when Black should preserve their light square bishop with ...Bd7} Bd6

3...Nf6
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 Nf6 4. e5 {White gains a bit of space in this line but not much else.} Nd5 5. Bxc4 Nb6 6. Bb3 Nc6 7. Be3 {7. Nge2 is also playable, but 7. Nf3?! walks into the pin 7...Bg4, which is uncomfortable, seeing as Black doesn't mind trading his bad bishop if the question is put to it.} Bf5 8. Nc3 e6 9. Nge2 Be7 10. O-O O-O

3...b5?!
[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 b5 4. a4 {White challenges the base of the pawn chain.} c6 {Black reinforces the base...} 5. b3 {...so white attacks the head of the chain instead!} e5 {Thematic and best. Over and over we will see ...e5 as been a crucial move in the 3. e4 QGA variations.} 6. axb5 cxb5 7. bxc4 Bb4+ {Black is desperate to gain counterplay (and material!) seeing as white's central pawns are so menacing.} 8. Bd2 {Forced. Blocking with Nd2 enters into an uncomfortable pin, and Ke2 loses castling rights and blocks up the kingside.} Qxd4 9. Bxb4 Qxa1 10. Nf3 {Despite white being down in material, White has: 1) More space, 2) Better development, 3) A vulnerable enemy king, queen and rooks to go after.}


-1: <p>What are the main ideas for White after 1. d4 d5 2. c4 dxc4 3. e4?</p>

<pre><code>[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4
</code></pre>
 -1: <p>Black has 4 main tries and one dubious line. White's plans vary based on the tabiya. The positions below are the lines given in <em>Starting Out: Queen's Gambit Accepted</em> by Reatsky and Chetverik:</p>

<h2>3...e5</h2>

<pre><code>[FEN ""]
[StartPly "5"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 {Best and thematic. A strong central counterattack that made the 3. e4 QGA unpopular in the '80s.} 4. Nf3 {White defends the pawn and prepares to castle kingside.}
</code></pre>

<p>Now Black has 2 choices: 4...Bb4+ and 4...exd4.</p>

<h2>4...Bb4+</h2>

<pre><code>[FEN ""]
[StartPly "7"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 4. Nf3 Bb4+ {Black develops with tempo and blocks a defender of the d4 pawn.} 5. Bd2 Bxd2+ {Black is happy to trade, seeing as he is up material and has slightly less space when the c4 pawn falls.} 6. Nbxd2 {6. Qxd2 exd4 7. Qxd4 Nf6 8. Qxd8+ Kxd8 actually sucks the venom out of white's attack, as the queens are gone and the trades benefit black, whose king is open and has less space.} exd4 7. Bxc4 Nc6 8. O-O Qf6 {Black aims to play ...Nge7 and ...O-O.} 9. e5 {The queen has developed early and can be attacked, gaining space. The pawn cannot be taken due to tactics on the open e-file.} Qg6 10. Re1 Nge7 11. Nb3 {Thematically regaining the pawn.} O-O 12. Nfxd4 {The material is now even with quite even development and safe kings. But why was it the f3 knight that recaptured? Well: 1) 12...Na5, pestering the bishop, is prevented, and 2) The queen can develop to the kingside, e.g. Qf3 easily.}
</code></pre>

<h2>4...exd4</h2>

<pre><code>[FEN ""]
[StartPly "7"]

  1. d4 d5 2. c4 dxc4 3. e4 e5 4. Nf3 exd4 {Black invites white to play 5. Qxd4? Qxd4 6. Nxd4 Bc5 which equalises. Similarly, 5. Nxd4? c5 6. Nf3 Qxd1+ is also good for black.} 5. Bxc4 {White should definitely develop the bishop to regain a pawn and take control of a key diagonal.} Nc6 6. O-O Be6 {Defending the diagonal leading to the weak f7 square, this almost forces a trade of a well developed piece.} 7. Bxe6 {7. Bb5 is playable. See Kaspaprov-Anand, Linares 1999} fxe6 8. Qb3 Qd7 {Why not 8...Qc8? Well this is too passive and can be punished by 9. Ng5!} 9. Qxb7 Rb8 10. Qa6 Nf6 11. Nbd2 Bd6 {The bishop develops to a flexible square that discourages e5.} 12. Qd3 O-O 13. a3 {Preventing any annoying ...Nb4 or ...Bb4 manoeuvres.} Ng4 {Black seeks to place a knight on e5, a well placed steed.} 14. b3 Nce5 15. Nxe5 Nxe5 16. Qxd4 Ng4 17. e5 Nxe5 18. Bb2 Rb5 19. Qe4 Nd3 20. Bd4 Rf4 21. Qa8+ Rf8 {With a likely draw by threefold repition.}
</code></pre>

<h2>3...c5</h2>

<pre><code>[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 c5 4. d5 Nf6 5. Nc3 b5 {Principle: attacked in the centre, counter on the wing} 6. Bf4 {The Bishop thematically comes to f4 as in some variations the bishop takes on b8, often in conjunction with a rook on b1.} Ba6 {Black has to develop rapidly, as the game is somewhat open and Black is being squeezed in the centre.} 7. e5 b4 8. exf6 bxc3 9. bxc3 gxf6 10. Bxc4 {This initiates a combination that simplifies into an endgame where white plays against the pawn weaknesses on c5 and the kingside.} Bxc4 11. Qa4+ Nd7 12. Qxc4 Nb6 13. Qb5+ Qd7 14. Qxd7+ Kxd7
</code></pre>

<h2>3...Nc6</h2>

<pre><code>[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 Nc6 4. Nf3 Bg4 5. d5 Ne5 6. Bf4 Ng6 {6...Nxf3 7. gxf3 Bd7 is not so strong for Black, as White now has a semi-open g-file to work with, and the White king is reasonably safe in the centre.} 7. Be3 e5 8. Bxc4 Nf6 9. Nc3 a6 {Black threatens to remove the defender of the e4 pawn with 10...b5 11. Be2 b4 12. Ng1 Nxe4} 10. Be2 {White would like to offer to trade the bad light square bishop with Nd2, when Black should preserve their light square bishop with ...Bd7} Bd6
</code></pre>

<h2>3...Nf6</h2>

<pre><code>[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 Nf6 4. e5 {White gains a bit of space in this line but not much else.} Nd5 5. Bxc4 Nb6 6. Bb3 Nc6 7. Be3 {7. Nge2 is also playable, but 7. Nf3?! walks into the pin 7...Bg4, which is uncomfortable, seeing as Black doesn't mind trading his bad bishop if the question is put to it.} Bf5 8. Nc3 e6 9. Nge2 Be7 10. O-O O-O
</code></pre>

<h2>3...b5?!</h2>

<pre><code>[FEN ""]
[StartPly "5"]

1. d4 d5 2. c4 dxc4 3. e4 b5 4. a4 {White challenges the base of the pawn chain.} c6 {Black reinforces the base...} 5. b3 {...so white attacks the head of the chain instead!} e5 {Thematic and best. Over and over we will see ...e5 as been a crucial move in the 3. e4 QGA variations.} 6. axb5 cxb5 7. bxc4 Bb4+ {Black is desperate to gain counterplay (and material!) seeing as white's central pawns are so menacing.} 8. Bd2 {Forced. Blocking with Nd2 enters into an uncomfortable pin, and Ke2 loses castling rights and blocks up the kingside.} Qxd4 9. Bxb4 Qxa1 10. Nf3 {Despite white being down in material, White has: 1) More space, 2) Better development, 3) A vulnerable enemy king, queen and rooks to go after.}
</code></pre>
