Answers.Body: <p>In the main line 5.d4, black responds with 5....d5 in order to occupy the centre and to continue his development. The most popular line continues with: 6.Bd3 Be7 7.0-0 Nc6! 8.c4 Nb4! 9.Be2 0-0 (e.g. <a href="http://www.chessgames.com/perl/chessgame?gid=1819914" rel="nofollow">Nakamura-Akobian</a>). Important to note: after 7....0-0 white has good chances to obtain an advantage after 8.c4.</p>
  
  <p>With 5.c4 white wants to discourage black to play ...d5. After 5....d5 white seems to obtain an advantage with 6.Nc3. 6....Nxc3 is very dubious: 7.dxc3 Be6 8.Ng5 with a big advantage for white.
  Instead, black often plays 5....Be7. After 6.d4 0-0 7.Bd3 d5 8.0-0 white has successfully transposed to 5.d4 d5 6.Bd3 Be7 7.0-0 0-0 8.c4 (<a href="http://www.chessgames.com/perl/chessgame?gid=1825642" rel="nofollow">Nepomniachtchi-Wang Hao (blitz)</a>).</p>
  
  <p>However, black has better alternatives after 5.c4, for example: </p>
  
  <ul>
  <li>5....Nc6 (<a href="http://www.chessgames.com/perl/chessgame?gid=1569709" rel="nofollow">Nisipeanu-Giri</a>) 6.d4 d5</li>
  <li>5....Be7 6.d4 Nc6 7.Bd3 Ng5</li>
  </ul>
  
  <pre>
  <code>
        [StartPly "8"]
  
        [FEN ""]
        1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.c4 (5.d4 d5 6.Bd3 Be7 7.O-O Nc6 (7...O-O 8.c4) 8.c4 Nb4 9.Be2 O-O) 5...Be7 (5...d5 6.Nc3 Nxc3 7.dxc3 Be6 8.Ng5)(5...Nc6 6.d4 d5) 6.d4 Nc6 (6...O-O 7.Bd3 d5 8.O-O) 7.Bd3 Ng5
  
  </code>
  </pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-08-18T14:10:30.763Z
Answers.Text: very helpful, I learned something both about the main lines, and about the Kaufmann attack itself (Petroff has always been confusing to study because of all possible move orders Black can choose; this sheds some light on this for me).
Answers.UserDisplayName: Joe
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-08-18T17:34:58.277Z
Answers.Text: You're welcome! Actually, by looking for games of top players, I also learned a couple of things myself.
Answers.UserDisplayName: Maxwell86
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-08-17T21:25:30.487Z
Answers.LastActivityDate: 2016-08-18T17:29:39.160Z
Answers.LastEditDate: 2016-08-18T17:29:39.160Z
Answers.UserDisplayName: Maxwell86
Answers.Body: <p>Just a tiny bit of history to explain the modern opening: It was Paul Morphy who started using the early ...Be7 and ...Nc6 which became the main line until the even more recent early Nc3 (without d4). However, Morphy had a penchant for ...f5 in many positions where it wasn't so wise, so 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O O-O 8. c4 f5 was his idea of securing the center. Today's players avoid that unless they're aiming for Pillsbury's idea of ...Bg4 and only then ...f5.</p>
  
  <p>All this is tossed out the window by Kaufmann (is it Larry Kaufmann?) who avoids all that.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-08-23T02:39:50.033Z
Answers.LastActivityDate: 2016-08-23T02:39:50.033Z
Answers.UserDisplayName: MarkH
Body: <p>What is the idea of White playing  1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. c4 ? Does he intend to get some good version of the main lines, while avoiding certain sidelines? It seems in fashion now with games like this one, but I am not sure I grasp the full concept - <a href="http://www.chessgames.com/perl/chessgame?gid=1820976" rel="nofollow">Ian Nepomniachtchi vs Sanan Sjugirov, 2016</a></p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2016-08-17T17:43:40.080Z
Comments.Text: I believe it is Kaufmann (with two "n"s).  (I'd edit it, but that's the only edit I have... and I believe there is a minimum number of characters.)
Comments.UserDisplayName: Ghotir
Tags: <opening><petroff-defense>
Title: What is the idea of the Kaufmann Attack (5.c4) against the Petroff?
ThreadText: # What is the idea of the Kaufmann Attack (5.c4) against the Petroff?
  
  (Asked by: username_0 on 2016-08-17)
  
  What is the idea of White playing 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. c4 ? Does he intend to get some good version of the main lines, while avoiding certain sidelines? It seems in fashion now with games like this one, but I am not sure I grasp the full concept - [Ian Nepomniachtchi vs Sanan Sjugirov, 2016](http://www.chessgames.com/perl/chessgame?gid=1820976)
  
  **Tags:** opening, petroff-defense
  
  > **Comments:**
  > **username_1**: I believe it is Kaufmann (with two "n"s).  (I'd edit it, but that's the only edit I have... and I believe there is a minimum number of characters.)  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_2 on 2016-08-17. Score: 5 | Accepted answer
  
  In the main line 5.d4, black responds with 5....d5 in order to occupy the centre and to continue his development. The most popular line continues with: 6.Bd3 Be7 7.0-0 Nc6! 8.c4 Nb4! 9.Be2 0-0 (e.g. [Nakamura-Akobian](http://www.chessgames.com/perl/chessgame?gid=1819914)). Important to note: after 7....0-0 white has good chances to obtain an advantage after 8.c4.
  
  With 5.c4 white wants to discourage black to play ...d5. After 5....d5 white seems to obtain an advantage with 6.Nc3. 6....Nxc3 is very dubious: 7.dxc3 Be6 8.Ng5 with a big advantage for white.
  Instead, black often plays 5....Be7. After 6.d4 0-0 7.Bd3 d5 8.0-0 white has successfully transposed to 5.d4 d5 6.Bd3 Be7 7.0-0 0-0 8.c4 ([Nepomniachtchi-Wang Hao (blitz)](http://www.chessgames.com/perl/chessgame?gid=1825642)).
  
  However, black has better alternatives after 5.c4, for example:
  
  * 5....Nc6 ([Nisipeanu-Giri](http://www.chessgames.com/perl/chessgame?gid=1569709)) 6.d4 d5
  * 5....Be7 6.d4 Nc6 7.Bd3 Ng5
  
  ```
  
        [StartPly "8"]
  
        [FEN ""]
        1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.c4 (5.d4 d5 6.Bd3 Be7 7.O-O Nc6 (7...O-O 8.c4) 8.c4 Nb4 9.Be2 O-O) 5...Be7 (5...d5 6.Nc3 Nxc3 7.dxc3 Be6 8.Ng5)(5...Nc6 6.d4 d5) 6.d4 Nc6 (6...O-O 7.Bd3 d5 8.O-O) 7.Bd3 Ng5
  
  ```
  
  > **Comments:**
  > **username_0**: very helpful, I learned something both about the main lines, and about the Kaufmann attack itself (Petroff has always been confusing to study because of all possible move orders Black can choose; this sheds some light on this for me).  
  > **username_2**: You're welcome! Actually, by looking for games of top players, I also learned a couple of things myself.  
  
  ---
  
  ### Answer by username_3 on 2016-08-23. Score: 0
  
  Just a tiny bit of history to explain the modern opening: It was Paul Morphy who started using the early ...Be7 and ...Nc6 which became the main line until the even more recent early Nc3 (without d4). However, Morphy had a penchant for ...f5 in many positions where it wasn't so wise, so 1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O O-O 8. c4 f5 was his idea of securing the center. Today's players avoid that unless they're aiming for Pillsbury's idea of ...Bg4 and only then ...f5.
  
  All this is tossed out the window by Kaufmann (is it Larry Kaufmann?) who avoids all that.
  
  
  ---
  
  