Answers.Body: <p>I almost always play <code>4. d4</code> instead of <code>4. d3</code>, to keep that line open for the bishop, and open up the game a bit as well. That's not to say <code>d3</code> isn't ok.</p>
  
  <p>Without computer analysis:
  That said, once they make the mistake of sacrificing that knight, you should quickly play <code>Be3</code> to defend against them double attacking your pinned knight. Once that is accomplished, you can play <code>Qe2</code> with the plan of castling queenside and evacuating your destroyed kingside pawn structure. Your goal should then be to carefully simplify by trading down until you get to an endgame where you're up a minor piece.</p>
  
  <p><img src="https://i.sstatic.net/Axjoa.png" alt="enter image description here"></p>
  
  <p>With computer analysis:
  Stockfish recommends playing <code>9. Nd5</code>, with the plan of playing <code>10. Ne3</code> for most responses, attacking the bishop on g4 (causing him to retreat with <code>...Bd7</code> or <code>...Be6</code>, probably. The great thing to notice here is that <code>9... Nd4</code> is not actually a threat, even though at first glance it appears to lose the knight on f3. After <code>9... Nd4</code>, White's tactic is as follows: <code>10. Nxd4! Bxd1 11. Bb5! Qd7</code> (there is no other option to prevent mate, either <code>11... Qd7</code> or <code>11... c6 12. Nxc6 bxc6 13. Bxc6 Qd7</code>). Bad news for black. After the dust settles it probably looks something like this.</p>
  
  <p><img src="https://i.sstatic.net/4jW8l.png" alt="enter image description here"></p>
  
  <p>Back to the main line: <code>9. Nd5</code>. Black can respond with a dozen reasonable moves (<code>...Na5</code>, <code>...Be7</code>, <code>...h5</code>, <code>...Qd7</code>, <code>...Qc7</code>, <code>...Qc8</code>, <code>...a6</code>, <code>...Rc8</code>, <code>...a5</code>, <code>...Rb8</code>), all of which follow with <code>10. Ne3</code> (except for <code>9... Bxf3</code>, in which case <code>10. Qxf3</code> is rather necessary). After this, you can start a kingside attack somewhat with <code>Rg1</code>, and getting your pieces out of the way for a castle queenside. You can turn your destroyed kingside pawns to your advantage by starting the attack there. Plenty of options from here on. You end up with something like:</p>
  
  <p><img src="https://i.sstatic.net/lXsF8.png" alt="enter image description here"></p>
  
  <p>For your second line, after you've already castled, I would not play <code>h3</code> + <code>g4</code>, which weakens your king's defenses (even if they don't sacrifice a piece there). If you really want to play <code>g4</code>, you can still recover with <code>Be3</code>, defending against <code>...Nd4</code>. They'll probably bring out the queen to attack (<code>...Qf6</code>), and you need to get your king out of there, undoing your castle to get your rook back outside of the king: <code>Kg2</code> followed by <code>Rg1</code> or <code>Rh1</code>. This situation isn't nearly as good for white; you'd be better off just avoiding <code>g4</code> after castling, at least at this early stage.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-06-13T04:43:32.057Z
Answers.Text: What about the situation where Black's black Bishop is also outside of the pawn chain? For example, in the third sequence, I've already castled Kingside before the pin happens. How should I resolve this pin after castling? Or perhaps, is it just a bad idea to castle when the Knight can be pinned?
Answers.UserDisplayName: Teofrostus
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-06-13T04:45:08.160Z
Answers.Text: I missed that you had another line there. Hang on I'll take a look.
Answers.UserDisplayName: Eve Freeman
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-06-13T04:46:52.970Z
Answers.Text: Also, I think you mean queenside castling in the second paragraph.
Answers.UserDisplayName: Teofrostus
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-06-14T02:24:06.790Z
Answers.Text: Added some images.
Answers.UserDisplayName: Eve Freeman
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-06-13T03:40:43.357Z
Answers.LastActivityDate: 2012-06-14T02:22:33.923Z
Answers.LastEditDate: 2012-06-14T02:22:33.923Z
Answers.UserDisplayName: Eve Freeman
Body: <p>I often get to play this opening :</p>
  
  <pre><code>[fen ""]
  1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d3 d6 5. Nc3 Bg4 (5... Be7 6. Be3 Bg4) (4... Bc5 5. Nc3 d6 6. O-O Bg4)
  </code></pre>
  
  <p>Sometimes there may be other moves or developments before the pin, like in the variations. In any case, now that my light squared bishop is outside my pawn chain, it's hard for it to come back and defend my knight on <code>f3</code>. So I usually feel like I need to kick the bishop from <code>g4</code> with a move like <code>h3</code>. After it retreats and <code>7.g4</code>, I'll sometimes see my pawns captured :</p>
  
  <pre><code>[fen "r2qkb1r/ppp2ppp/2np1n2/4p3/2B1P1b1/2NP1N2/PPP2PPP/R1BQK2R w - - 0 6"]
  
  6. h3 Bh5 7. g4 Nxg4 8. hxg4 Bxg4 (7... Bg6)
  </code></pre>
  
  <p>I looked at this position in Rybka and used the Chess.com computers to analyze the position, both of which label <code>7... Nxg4</code> as a mistake. However, I'm not sure how to punish this mistake, as afterwards, my knight is still pinned to the queen, and my bishop on <code>c4</code> still can't find any good way to come back and defend.</p>
  
  <p>Can someone explain to me the correct way to continue this position as white? I usually find myself losing the knight on <code>f3</code>, and eventually lose the position. Here is a link to the position in <a href="http://www.chess.com/explorer/index.html?black=0&amp;ply=10&amp;id=759938" rel="noreferrer">Chess.com's Game explorer</a>. It isn't seen very often at master level play.</p>
  
Tags: <opening><sacrifice><two-knights><italian-game>
Title: How should I defend against this sacrifice in the Two Knights Defense?
ThreadText: # How should I defend against this sacrifice in the Two Knights Defense?
  
  (Asked by: username_0 on 2012-06-13)
  
  I often get to play this opening :
  
  ```
  [fen ""]
  1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d3 d6 5. Nc3 Bg4 (5... Be7 6. Be3 Bg4) (4... Bc5 5. Nc3 d6 6. O-O Bg4)
  
  ```
  
  Sometimes there may be other moves or developments before the pin, like in the variations. In any case, now that my light squared bishop is outside my pawn chain, it's hard for it to come back and defend my knight on `f3`. So I usually feel like I need to kick the bishop from `g4` with a move like `h3`. After it retreats and `7.g4`, I'll sometimes see my pawns captured :
  
  ```
  [fen "r2qkb1r/ppp2ppp/2np1n2/4p3/2B1P1b1/2NP1N2/PPP2PPP/R1BQK2R w - - 0 6"]
  
  6. h3 Bh5 7. g4 Nxg4 8. hxg4 Bxg4 (7... Bg6)
  
  ```
  
  I looked at this position in Rybka and used the Chess.com computers to analyze the position, both of which label `7... Nxg4` as a mistake. However, I'm not sure how to punish this mistake, as afterwards, my knight is still pinned to the queen, and my bishop on `c4` still can't find any good way to come back and defend.
  
  Can someone explain to me the correct way to continue this position as white? I usually find myself losing the knight on `f3`, and eventually lose the position. Here is a link to the position in [Chess.com's Game explorer](http://www.chess.com/explorer/index.html?black=0&ply=10&id=759938). It isn't seen very often at master level play.
  
  **Tags:** opening, sacrifice, two-knights, italian-game
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2012-06-13. Score: 9 | Accepted answer
  
  I almost always play `4. d4` instead of `4. d3`, to keep that line open for the bishop, and open up the game a bit as well. That's not to say `d3` isn't ok.
  
  Without computer analysis:
  That said, once they make the mistake of sacrificing that knight, you should quickly play `Be3` to defend against them double attacking your pinned knight. Once that is accomplished, you can play `Qe2` with the plan of castling queenside and evacuating your destroyed kingside pawn structure. Your goal should then be to carefully simplify by trading down until you get to an endgame where you're up a minor piece.
  
  ![enter image description here](https://i.sstatic.net/Axjoa.png)
  
  With computer analysis:
  Stockfish recommends playing `9. Nd5`, with the plan of playing `10. Ne3` for most responses, attacking the bishop on g4 (causing him to retreat with `...Bd7` or `...Be6`, probably. The great thing to notice here is that `9... Nd4` is not actually a threat, even though at first glance it appears to lose the knight on f3. After `9... Nd4`, White's tactic is as follows: `10. Nxd4! Bxd1 11. Bb5! Qd7` (there is no other option to prevent mate, either `11... Qd7` or `11... c6 12. Nxc6 bxc6 13. Bxc6 Qd7`). Bad news for black. After the dust settles it probably looks something like this.
  
  ![enter image description here](https://i.sstatic.net/4jW8l.png)
  
  Back to the main line: `9. Nd5`. Black can respond with a dozen reasonable moves (`...Na5`, `...Be7`, `...h5`, `...Qd7`, `...Qc7`, `...Qc8`, `...a6`, `...Rc8`, `...a5`, `...Rb8`), all of which follow with `10. Ne3` (except for `9... Bxf3`, in which case `10. Qxf3` is rather necessary). After this, you can start a kingside attack somewhat with `Rg1`, and getting your pieces out of the way for a castle queenside. You can turn your destroyed kingside pawns to your advantage by starting the attack there. Plenty of options from here on. You end up with something like:
  
  ![enter image description here](https://i.sstatic.net/lXsF8.png)
  
  For your second line, after you've already castled, I would not play `h3` + `g4`, which weakens your king's defenses (even if they don't sacrifice a piece there). If you really want to play `g4`, you can still recover with `Be3`, defending against `...Nd4`. They'll probably bring out the queen to attack (`...Qf6`), and you need to get your king out of there, undoing your castle to get your rook back outside of the king: `Kg2` followed by `Rg1` or `Rh1`. This situation isn't nearly as good for white; you'd be better off just avoiding `g4` after castling, at least at this early stage.
  
  > **Comments:**
  > **username_0**: What about the situation where Black's black Bishop is also outside of the pawn chain? For example, in the third sequence, I've already castled Kingside before the pin happens. How should I resolve this pin after castling? Or perhaps, is it just a bad idea to castle when the Knight can be pinned?  
  > **username_1**: I missed that you had another line there. Hang on I'll take a look.  
  > **username_0**: Also, I think you mean queenside castling in the second paragraph.  
  > **username_1**: Added some images.  
  
  ---
  
  