Answers.Body: <p>Here is one possible answer: there is an <a href="https://github.com/niklasf/eco" rel="noreferrer">eco.json</a> file available which is based on the <em>Encyclopedia of Chess Openings</em>. If you take the contents of that file and sort the openings by the length of the line leading to the named position, there is a unique winner, the 36 plies long <em>Ruy Lopez: Marshall, Main Line, Spassky Variation</em>:</p>
  
  <pre><code>{'c': 'C89',
   'f': '5rk1/5ppp/p1pbr3/1p1n3q/P2P2b1/1BPQB1P1/1P1N1P1P/R3R1K1 w -',
   'id': 3320,
   'm': 'e2e4 e7e5 g1f3 b8c6 f1b5 a7a6 b5a4 g8f6 e1g1 f8e7 f1e1 b7b5 a4b3 e8g8 c2c3 d7d5 e4d5 f6d5 f3e5 c6e5 e1e5 c7c6 d2d4 e7d6 e5e1 d8h4 g2g3 h4h3 c1e3 c8g4 d1d3 a8e8 b1d2 e8e6 a2a4 h3h5',
   'n': 'Ruy Lopez: Marshall, Main Line, Spassky Variation'}
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-30T23:06:57.930Z
Answers.Text: This answered my question precisely. Thanks!
Answers.UserDisplayName: Marvin
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-30T11:05:22.367Z
Answers.LastActivityDate: 2019-05-30T11:05:22.367Z
Answers.UserDisplayName: itub
Body: <p>For most openings that I play (e4 and d4 openings) I have observed that they take exactly 4 moves (e.g. Giuoco Piano Game without variation). </p>
  
  <p>C50: Giuoco Pianissimo, Italian four knights variation takes 5 moves. 
  The Van't Kruijs Opening (1. e3) takes less than 1. </p>
  
  <p>Which opening requires the longest amount of chess moves?</p>
  
  <h2>Edit</h2>
  
  <p>As I see I have been unclear, let me clarify. When I say two distinct openings, all I mean is a different name. For example, Ruy Loypez, XXX Variation is different from Ruy Lopez Ppening is different from Ruy Lopez, YYY Variation. </p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-30T01:19:59.343Z
Comments.Text: Depends on what you call an "opening". Certain systems can start after move 20, but they aren't mainstream openings one thinks of.
Comments.UserDisplayName: Inertial Ignorance
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-30T01:22:48.923Z
Comments.Text: The openings you mention have theory well beyond the fourth move.
Comments.UserDisplayName: Qudit
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-30T06:28:24.973Z
Comments.Text: At the moment, the question is unclear: when do you consider two lines different openings? You could ask for the two ECO codes sharing the highest amount of moves, that would be objectively answerable.
Comments.UserDisplayName: Glorfindel
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-30T06:38:42.683Z
Comments.Text: @Qudit You didn't understand the question. It's aobut the number of moves to reach a certain opening, which I don't think has an answer, as there is no clear definition of what two distinct openings are
Comments.UserDisplayName: David
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-30T21:28:57.813Z
Comments.Text: @glorfindel I have made an edit to my post
Comments.UserDisplayName: Marvin
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-31T09:34:11.393Z
Comments.Text: Maybe 'what is the latest named opening position' or so?
Comments.UserDisplayName: RemcoGerlich
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-31T11:36:30.797Z
Comments.Text: @RemcoGerlich Correct.
Comments.UserDisplayName: Marvin
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-31T20:47:34.157Z
Comments.Text: I believe this question should be reopened considering that I have edited the question, gotten an answer, and accepted the answer.
Comments.UserDisplayName: Marvin
Tags: <opening>
Title: Which opening requires the longest amount of chess moves?
ThreadText: # Which opening requires the longest amount of chess moves?
  
  (Asked by: username_0 on 2019-05-29)
  
  For most openings that I play (e4 and d4 openings) I have observed that they take exactly 4 moves (e.g. Giuoco Piano Game without variation).
  
  C50: Giuoco Pianissimo, Italian four knights variation takes 5 moves.
  The Van't Kruijs Opening (1. e3) takes less than 1.
  
  Which opening requires the longest amount of chess moves?
  
  ## Edit
  
  As I see I have been unclear, let me clarify. When I say two distinct openings, all I mean is a different name. For example, Ruy Loypez, XXX Variation is different from Ruy Lopez Ppening is different from Ruy Lopez, YYY Variation.
  
  **Tags:** opening
  
  > **Comments:**
  > **username_1**: Depends on what you call an "opening". Certain systems can start after move 20, but they aren't mainstream openings one thinks of.  
  > **username_2**: The openings you mention have theory well beyond the fourth move.  
  > **username_3**: At the moment, the question is unclear: when do you consider two lines different openings? You could ask for the two ECO codes sharing the highest amount of moves, that would be objectively answerable.  
  > **username_4**: @username_2 You didn't understand the question. It's aobut the number of moves to reach a certain opening, which I don't think has an answer, as there is no clear definition of what two distinct openings are  
  > **username_0**: @username_3 I have made an edit to my post  
  > **username_5**: Maybe 'what is the latest named opening position' or so?  
  > **username_0**: @username_5 Correct.  
  > **username_0**: I believe this question should be reopened considering that I have edited the question, gotten an answer, and accepted the answer.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_6 on 2019-05-30. Score: 6 | Accepted answer
  
  Here is one possible answer: there is an [eco.json](https://github.com/niklasf/eco) file available which is based on the *Encyclopedia of Chess Openings*. If you take the contents of that file and sort the openings by the length of the line leading to the named position, there is a unique winner, the 36 plies long *Ruy Lopez: Marshall, Main Line, Spassky Variation*:
  
  ```
  {'c': 'C89',
   'f': '5rk1/5ppp/p1pbr3/1p1n3q/P2P2b1/1BPQB1P1/1P1N1P1P/R3R1K1 w -',
   'id': 3320,
   'm': 'e2e4 e7e5 g1f3 b8c6 f1b5 a7a6 b5a4 g8f6 e1g1 f8e7 f1e1 b7b5 a4b3 e8g8 c2c3 d7d5 e4d5 f6d5 f3e5 c6e5 e1e5 c7c6 d2d4 e7d6 e5e1 d8h4 g2g3 h4h3 c1e3 c8g4 d1d3 a8e8 b1d2 e8e6 a2a4 h3h5',
   'n': 'Ruy Lopez: Marshall, Main Line, Spassky Variation'}
  
  ```
  
  > **Comments:**
  > **username_0**: This answered my question precisely. Thanks!  
  
  ---
  
  