Answers.Body: <p>9 ... Be7 is a normal developing move preparing to castle next move.</p>
  <p>10 ...Ng8 reflects a change in plan given white's change to the pawn structure. On f6 the black knight was doing a good job attacking the e4 pawn. When it moved to e5 attacking the knight, forcing it to move, that changed. The only two squares that don't lose the knight are h5 and g8. On h5 the knight has no moves and no prospects. That leaves just g8 but raises the problem where is the knight going to go?</p>
  <p>11 ...Bf8 solves the problem of the knight. It allows the knight to relocate to the active square f5 via e7.</p>
  <blockquote>
  <p>What can we learn from them?</p>
  </blockquote>
  <p>This is a classic example of a good player having the flexibility to change plans in response to the opponent's moves even at the cost of undeveloping one or two pieces. One of the most common mistakes of intermediate players is to play &quot;formula&quot; chess where the same opening moves are banged out regardless of the opponent's moves.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-03-18T23:32:15.807Z
Answers.LastActivityDate: 2023-03-18T23:32:15.807Z
Answers.UserDisplayName: Brian Towers
Body: <p>I am amazed by Petrosian's manoeuvre 9. ... Be7 10. ... Ng8 11. ... Bf8 in the <a href="https://www.chessgames.com/perl/chessgame?gid=1106554" rel="nofollow noreferrer">following game</a>:</p>
  <pre><code>[Title &quot;Benko - Petrosian, Curacao 1962&quot;]
  [fen &quot;&quot;]
  [Startply &quot;17&quot;]
  
  1. g3 d5 2. Nf3 c6 3. Bg2 Bf5 4. O-O e6 5. d3 Nf6 6. Nbd2 Nbd7 7. Qe1 h6 8. e4 Bh7 9. Qe2 Be7 10. e5 Ng8 11. Nb3 Bf8 12. c4 Ne7 13. Nfd4 Nf5 14. Nxf5 Bxf5 15. cxd5 cxd5 16. d4 a5 17. Be3 Be7 18. Rfc1 O-O 19. Qb5 a4 20. Nd2 Ra7 21. Nb1 Nb8 22. a3 Nc6 23. Nc3 Qa5 24. Bf1 f6 25. f4 fxe5 26. fxe5 Bg5 27. Bxg5 hxg5 28. Qxa5 Rxa5 29. Rd1 Raa8 30. Bb5 Na5 31. Bxa4 Nc4 32. b3 Nb2 33. Rdc1 Nxa4 34. Nxa4 Bh3 35. Ra2 Rf3 36. Rf2 Rxb3 37. Nc5 Rbxa3 38. Nxb7 Rd3 39. Nd6 Kh7 40. Nb5 Rb8 41. Rb2 Rf3 42. Rbb1 Bf5 43. Rb2 g4 0-1
  </code></pre>
  <p>These three moves (9. ... Be7 10. ... Ng8 11. ... Bf8) seem to violate a lot of opening principles and undevelop his pieces. Are they really good moves? What can we learn from them?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-03-18T07:07:17.173Z
Comments.Text: Might be wrong, but it feels that your questions are a bit broad and could be combined into one, clear stance.
Comments.UserDisplayName: Rewan Demontay
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-03-18T07:34:09.533Z
Comments.Text: when center is closed you can afford to waste tempi?
Comments.UserDisplayName: cmgchess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-03-18T07:45:38.490Z
Comments.Text: somewhat similar 1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 b6 5. a3 Bf8. so probably blacks plan was to lure white to play e5
Comments.UserDisplayName: cmgchess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-03-18T11:01:41.120Z
Comments.Text: Opening principles are general guidelines for beginners, not set-in-stone rules. Also whoever voted to close this question deserves a permanent ban from the site.
Comments.UserDisplayName: David
Tags: <opening><development>
Title: Petrosian's 9. ... Be7 10. ... Ng8 11. ... Bf8
ThreadText: # Petrosian's 9. ... Be7 10. ... Ng8 11. ... Bf8
  
  (Asked by: username_0 on 2023-03-18)
  
  I am amazed by Petrosian's manoeuvre 9. ... Be7 10. ... Ng8 11. ... Bf8 in the [following game](https://www.chessgames.com/perl/chessgame?gid=1106554):
  
  ```
  [Title "Benko - Petrosian, Curacao 1962"]
  [fen ""]
  [Startply "17"]
  
  1. g3 d5 2. Nf3 c6 3. Bg2 Bf5 4. O-O e6 5. d3 Nf6 6. Nbd2 Nbd7 7. Qe1 h6 8. e4 Bh7 9. Qe2 Be7 10. e5 Ng8 11. Nb3 Bf8 12. c4 Ne7 13. Nfd4 Nf5 14. Nxf5 Bxf5 15. cxd5 cxd5 16. d4 a5 17. Be3 Be7 18. Rfc1 O-O 19. Qb5 a4 20. Nd2 Ra7 21. Nb1 Nb8 22. a3 Nc6 23. Nc3 Qa5 24. Bf1 f6 25. f4 fxe5 26. fxe5 Bg5 27. Bxg5 hxg5 28. Qxa5 Rxa5 29. Rd1 Raa8 30. Bb5 Na5 31. Bxa4 Nc4 32. b3 Nb2 33. Rdc1 Nxa4 34. Nxa4 Bh3 35. Ra2 Rf3 36. Rf2 Rxb3 37. Nc5 Rbxa3 38. Nxb7 Rd3 39. Nd6 Kh7 40. Nb5 Rb8 41. Rb2 Rf3 42. Rbb1 Bf5 43. Rb2 g4 0-1
  
  ```
  
  These three moves (9. ... Be7 10. ... Ng8 11. ... Bf8) seem to violate a lot of opening principles and undevelop his pieces. Are they really good moves? What can we learn from them?
  
  **Tags:** opening, development
  
  > **Comments:**
  > **username_1**: Might be wrong, but it feels that your questions are a bit broad and could be combined into one, clear stance.  
  > **username_2**: when center is closed you can afford to waste tempi?  
  > **username_2**: somewhat similar 1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 b6 5. a3 Bf8. so probably blacks plan was to lure white to play e5  
  > **username_3**: Opening principles are general guidelines for beginners, not set-in-stone rules. Also whoever voted to close this question deserves a permanent ban from the site.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_4 on 2023-03-18. Score: 6 | Accepted answer
  
  9 ... Be7 is a normal developing move preparing to castle next move.
  
  10 ...Ng8 reflects a change in plan given white's change to the pawn structure. On f6 the black knight was doing a good job attacking the e4 pawn. When it moved to e5 attacking the knight, forcing it to move, that changed. The only two squares that don't lose the knight are h5 and g8. On h5 the knight has no moves and no prospects. That leaves just g8 but raises the problem where is the knight going to go?
  
  11 ...Bf8 solves the problem of the knight. It allows the knight to relocate to the active square f5 via e7.
  
  > What can we learn from them?
  
  This is a classic example of a good player having the flexibility to change plans in response to the opponent's moves even at the cost of undeveloping one or two pieces. One of the most common mistakes of intermediate players is to play "formula" chess where the same opening moves are banged out regardless of the opponent's moves.
  
  
  ---
  
  