Answers.Body: <p>There's no universal definition of what constitutes a mainline move. It also changes through time, so in this case 3.Nc3 may have been the mainline before but not anymore.</p>
  <p>Anyway I don't think I've heard &quot;mainline Caro-Kann&quot; to refer to 3.Nc3, but rather &quot;Classical Caro-Kann&quot;.</p>
  
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Answers.CreationDate: 2022-11-24T10:03:34.717Z
Answers.LastActivityDate: 2022-11-24T10:03:34.717Z
Answers.UserDisplayName: David
Body: <p>After 1.e4 c6, 2. d4 d5, the move 3. Nc3 is called the &quot;mainline&quot;. According to lichess's database, the move 3. e5 has been played more than 3. Nc3, both by masters and by non-masters. This makes me wonder why we don't call 3. e5 the &quot;mainline&quot;.</p>
  <p>In general, what makes an opening move the &quot;mainline&quot;? Is it not the most popular move?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-11-24T07:52:38.623Z
Comments.Text: I couldn't find where it says mainline for 3.Nc3. Can you give reference? Lichess and Wikipedia says 2.d4 d5 is the mainline and the rest is named differently, classical, modern, advance etc.
Comments.UserDisplayName: Minot
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-11-24T07:58:56.143Z
Comments.Text: One thing to note is that 3.Nc3 and 3.Nd2 are essentially the same, so a fairer comparison may be to compare the popularity of 3.Nc3 + 3.Nd2 vs 3.e5.
Comments.UserDisplayName: Inertial Ignorance
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-11-24T08:40:12.730Z
Comments.Text: It may also be a function of time - in the Benoni you get the "Classical" and "Modern main line". I suspect this might be happening here, the popularity of the advance Caro-Kann is relatively recent.
Comments.UserDisplayName: Ian Bush
Tags: <opening><terminology><caro-kann>
Title: What makes an opening move the "mainline"?
ThreadText: # What makes an opening move the "mainline"?
  
  (Asked by: username_0 on 2022-11-24)
  
  After 1.e4 c6, 2. d4 d5, the move 3. Nc3 is called the "mainline". According to lichess's database, the move 3. e5 has been played more than 3. Nc3, both by masters and by non-masters. This makes me wonder why we don't call 3. e5 the "mainline".
  
  In general, what makes an opening move the "mainline"? Is it not the most popular move?
  
  **Tags:** opening, terminology, caro-kann
  
  > **Comments:**
  > **username_1**: I couldn't find where it says mainline for 3.Nc3. Can you give reference? Lichess and Wikipedia says 2.d4 d5 is the mainline and the rest is named differently, classical, modern, advance etc.  
  > **username_2**: One thing to note is that 3.Nc3 and 3.Nd2 are essentially the same, so a fairer comparison may be to compare the popularity of 3.Nc3 + 3.Nd2 vs 3.e5.  
  > **username_3**: It may also be a function of time - in the Benoni you get the "Classical" and "Modern main line". I suspect this might be happening here, the popularity of the advance Caro-Kann is relatively recent.  
  
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  ## 1 answers
  
  ### Answer by username_4 on 2022-11-24. Score: 5
  
  There's no universal definition of what constitutes a mainline move. It also changes through time, so in this case 3.Nc3 may have been the mainline before but not anymore.
  
  Anyway I don't think I've heard "mainline Caro-Kann" to refer to 3.Nc3, but rather "Classical Caro-Kann".
  
  
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