Answers.Body: <p>The point is that after 8...h6, White can now play 9.Ne4. Comparatively, after 8.Be2 h6, White must go for 9.Nf3 e4, when the knight is hit again.</p>
  
  <p>You're right that 8.Bd3 blocks the d2-pawn from advancing, but this isn't such a huge price to pay. The c1-bishop can get into the game via b3 followed by Bb2.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-03T04:02:42.990Z
Answers.Text: In this line of the 4 Knights, White always has a problem disentangling his pieces. His consolation in all cases is the poorly placed Black Na5.
Answers.UserDisplayName: Philip Roe
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-02T21:52:29.070Z
Answers.LastActivityDate: 2019-09-02T21:52:29.070Z
Answers.UserDisplayName: Inertial Ignorance
Answers.Body: <p>I think this move illustrates the problem with &quot;opening principles&quot;. Sometimes they contradict one another!</p>
  <p>For example, 8.Be2 may appear more natural because it does not block the &quot;d&quot; pawn. However, it also places the bishop in a passive square as, as indicated by Mike Jones, does not allow for <code>Ne4</code> later on.</p>
  <p>Finally, <code>Qf3</code>-related ideas may still be playable after <code>8.Bd3</code></p>
  
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Answers.CreationDate: 2019-09-02T08:02:02.513Z
Answers.LastActivityDate: 2022-03-04T16:27:06.007Z
Answers.LastEditDate: 2022-03-04T16:27:06.007Z
Answers.UserDisplayName: David
Answers.Body: <p>I think it's helpful to think of bishop hoping to go to f1, after O-O and Re1. Good illustrative game is Lev Aronian v. Vidit Gujrathi Kolkata 2019 (Rapid &amp; Blitz): <a href="https://www.chessgames.com/perl/chessgame?gid=1981131" rel="nofollow noreferrer">https://www.chessgames.com/perl/chessgame?gid=1981131</a></p>
  
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Answers.UserDisplayName: Robert Couch
Answers.Body: <p>I think the main reason behind Bd3 is to provide a "safe" retreat for the knight and keeps to e-file open.  Both Nf3 and Nh3 have liabilities. A retreat to e4 also allow a further lose of time from f5, but this may be offset by black's LSB having less mobility.  The other option is Bf1, which while playable, also goes against basic opening principles.</p>
  
  <p>Although this may apply here, paraphrasing Alekhine, to punish unconventional moves (Na5) you may have to play unconventional moves.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-08-31T17:07:41.157Z
Answers.Text: Indeed, well put. `8.Bd3` is a very concrete move to prevent a poor knight retreat after `8...h6.` Since black's position has already opened up in this line, white's priorities lie in not having bad pieces and in particular neutralizing black's best piece, the knight on `f6.` In case black side-steps the trade with `9...Nd5` white usually ends up finishing development with `Ng3...Bf5...e3...Nc3.`
Answers.UserDisplayName: Ellie
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-08-31T17:48:42.167Z
Answers.Text: What is White doing after 8...h6 9.Ne4 Nxe4 10.Bxe4 f5?
Answers.UserDisplayName: A. N. Other
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-08-31T18:57:39.027Z
Answers.Text: @A.N.Other It seems like black's king becomes very unsafe after 10...f5, since Qh5+ is on tap, followed by picking up the pawn on f5 for free.
Answers.UserDisplayName: Scounged
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-08-31T21:33:38.673Z
Answers.Text: `Qf3` seems to have a similar effect with supporting a retreat to e5, though it looks a bit more dubious.
Answers.UserDisplayName: konsolas
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Answers.CreationDate: 2019-08-31T16:16:24.443Z
Answers.LastActivityDate: 2019-08-31T16:16:24.443Z
Answers.UserDisplayName: Mike Jones
Body: <p>In the Two Knights Defense, after </p>
  
  <pre><code>[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
  1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6
  </code></pre>
  
  <p><code>8. Bd3</code> has become fashionable recently, and is considered a serious way for White to play for a win. </p>
  
  <p>Yet, is seems an artificial move, going against basic opening principles, in particular blocking the d-Pawn. What are the main points of this line, especially in comparison to the "old" <code>8. Be2</code> move, and are there any typical traps or pitfalls to be aware of? </p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-08-31T12:51:57.180Z
Comments.Text: `Bd3` is actually favoured by a number of high level engines, so I think it would be very interesting to know about the theory behind that move.
Comments.UserDisplayName: konsolas
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-09-03T08:50:11.443Z
Comments.Text: Hi, this post seems to have received a number of decent answers, if you have found one to be particularly satisfactory please consider [accepting](https://meta.stackexchange.com/q/5234) it, as it's important to give [closure](https://meta.stackexchange.com/a/163743) to well addressed posts. Thanks for considering it.
Comments.UserDisplayName: user929304
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-09-03T10:46:39.140Z
Comments.Text: Sure, it’s just that all these answers are equally good in my view. I’ll try to select one anyway. :)
Comments.UserDisplayName: A. N. Other
Tags: <opening><1.e4><two-knights>
Title: Ideas behind the 8.Bd3 line in the 4.Ng5 Two Knights Defense
ThreadText: # Ideas behind the 8.Bd3 line in the 4.Ng5 Two Knights Defense
  
  (Asked by: username_0 on 2019-08-31)
  
  In the Two Knights Defense, after
  
  ```
  [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
  1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+ c6 7.dxc6 bxc6
  
  ```
  
  `8. Bd3` has become fashionable recently, and is considered a serious way for White to play for a win.
  
  Yet, is seems an artificial move, going against basic opening principles, in particular blocking the d-Pawn. What are the main points of this line, especially in comparison to the "old" `8. Be2` move, and are there any typical traps or pitfalls to be aware of?
  
  **Tags:** opening, 1.e4, two-knights
  
  > **Comments:**
  > **username_1**: `Bd3` is actually favoured by a number of high level engines, so I think it would be very interesting to know about the theory behind that move.  
  > **username_2**: Hi, this post seems to have received a number of decent answers, if you have found one to be particularly satisfactory please consider [accepting](https://meta.stackexchange.com/q/5234) it, as it's important to give [closure](https://meta.stackexchange.com/a/163743) to well addressed posts. Thanks for considering it.  
  > **username_0**: Sure, it’s just that all these answers are equally good in my view. I’ll try to select one anyway. :)  
  
  ---
  
  ## 4 answers
  
  ### Answer by username_7 on 2019-08-31. Score: 13 | Accepted answer
  
  I think the main reason behind Bd3 is to provide a "safe" retreat for the knight and keeps to e-file open. Both Nf3 and Nh3 have liabilities. A retreat to e4 also allow a further lose of time from f5, but this may be offset by black's LSB having less mobility. The username_0 option is Bf1, which while playable, also goes against basic opening principles.
  
  Although this may apply here, paraphrasing Alekhine, to punish unconventional moves (Na5) you may have to play unconventional moves.
  
  > **Comments:**
  > **username_8**: Indeed, well put. `8.Bd3` is a very concrete move to prevent a poor knight retreat after `8...h6.` Since black's position has already opened up in this line, white's priorities lie in not having bad pieces and in particular neutralizing black's best piece, the knight on `f6.` In case black side-steps the trade with `9...Nd5` white usually ends up finishing development with `Ng3...Bf5...e3...Nc3.`  
  > **username_0**: What is White doing after 8...h6 9.Ne4 Nxe4 10.Bxe4 f5?  
  > **username_9**: @username_0 It seems like black's king becomes very unsafe after 10...f5, since Qh5+ is on tap, followed by picking up the pawn on f5 for free.  
  > **username_1**: `Qf3` seems to have a similar effect with supporting a retreat to e5, though it looks a bit more dubious.  
  
  ---
  
  ### Answer by username_3 on 2019-09-02. Score: 5
  
  The point is that after 8...h6, White can now play 9.Ne4. Comparatively, after 8.Be2 h6, White must go for 9.Nf3 e4, when the knight is hit again.
  
  You're right that 8.Bd3 blocks the d2-pawn from advancing, but this isn't such a huge price to pay. The c1-bishop can get into the game via b3 followed by Bb2.
  
  > **Comments:**
  > **username_4**: In this line of the 4 Knights, White always has a problem disentangling his pieces. His consolation in all cases is the poorly placed Black Na5.  
  
  ---
  
  ### Answer by username_5 on 2019-09-02. Score: 4
  
  I think this move illustrates the problem with "opening principles". Sometimes they contradict one another!
  
  For example, 8.Be2 may appear more natural because it does not block the "d" pawn. However, it also places the bishop in a passive square as, as indicated by username_7 username_7, does not allow for `Ne4` later on.
  
  Finally, `Qf3`-related ideas may still be playable after `8.Bd3`
  
  
  ---
  
  ### Answer by username_6 on 2022-03-02. Score: 1
  
  I think it's helpful to think of bishop hoping to go to f1, after O-O and Re1. Good illustrative game is Lev Aronian v. Vidit Gujrathi Kolkata 2019 (Rapid & Blitz): <https://www.chessgames.com/perl/chessgame?gid=1981131>
  
  
  ---
  
  