Answers.Body: <blockquote>
  <p>the absence of Black's C pawn and the fight against the D5 square</p>
  </blockquote>
  <p>That's more or less it. This kind of position is most probably the result of a Sicilian. Could it be something else? It can, but the Sicilian is the most likely opening.</p>
  <blockquote>
  <p>can we reverse engineer every middle game position to an opening</p>
  </blockquote>
  <p>No. This position for example is a middlegame with no clear signposts as to what opening led to it.</p>
  <pre><code>[FEN &quot;rn1r2k1/pp2qppp/8/8/3N2n1/1N2P3/P1Q2PPP/R4RK1 w - - 0 18&quot;]
  </code></pre>
  <p>Here's another example. It should be decently clear which opening this game began with. If not, imagine Black playing ...f5 and White taking with exf5.</p>
  <pre><code>[FEN &quot;r1bqk2r/pppn2bp/3p4/3Ppp2/2P5/2N1BP2/PP4PP/R2QKB1R w KQkq - 0 12&quot;]
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-17T09:14:09.267Z
Answers.Text: That is exactly what I was asking for. AFAIU, more or less, some openings have more characteristics then other, leading to a more likely-to-see middle games :)
Answers.UserDisplayName: Sinan Yaman
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-17T15:04:09.927Z
Answers.Text: Can someone clarify what should be the opening in the last, more clear example? Thanks.
Answers.UserDisplayName: Daniel Alfredo Sottile
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-17T23:36:39.953Z
Answers.Text: @DanielAlfredoSottile the second diagram is a [King's Indian](https://en.wikipedia.org/wiki/King%27s_Indian_Defence). From the classical variation diagram, White played d5, Black played ...f5, and there followed exf5 gxf5.
Answers.UserDisplayName: Allure
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-19T20:28:58.963Z
Answers.Text: The point of identifying the opening is that it should bring to mind the standard strategies that the opening leads to. Although the second diagram is certsinly "Kings-Indian-ish" it is far from being typical. Black has not castled and a pair of Knights have vanished through some nonstandard exchange. I would have great difficulty constructing a plausibe move sequence leading to this position and I do not see how to adapt much of my KI know-how.
Answers.UserDisplayName: Philip Roe
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-21T05:53:39.007Z
Answers.Text: @PhilipRoe 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 e5 6. Nge2 Nc6 7. d5 Ne7 8. Ng3 Nd7 9. Be3 f5 10. exf5 Nxf5 11. Nxf5 gxf5
Answers.UserDisplayName: Allure
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-22T05:06:37.283Z
Answers.Text: @allure Thank you. Your reconstruction is very sensible and not as hard as I implied. Although It still doesnt ring many of my KI bells. Perhaps more thematic 8.Nc1 intending b4 Nb3 with a typical Q-side pus, against what will be a typical Black K-side push.
Answers.UserDisplayName: Philip Roe
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-17T08:53:53.260Z
Answers.LastActivityDate: 2022-01-17T08:53:53.260Z
Answers.UserDisplayName: Allure
Answers.Body: <p>The biggest clue is the pawn structure. Allure's first diagram hints that is was a Grunfeld due to the queenside pawns.  (Although since there are so many transpositions that the opening can change on a move's notice.)  The further the game proceeds, the harder it becomes to guess the opening.</p>
  <p>As a teen, I played the Blackmar–Diemer Gambit, which had the trait of white missing the e and f pawns.  However, black could transpose into the French or the Caro-Kann, making a d pawn into an e pawn opening.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-17T14:16:59.917Z
Answers.Text: You sure the first diagram looks like a Grunfeld? It doesn't have ...g6.
Answers.UserDisplayName: Allure
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-17T13:41:15.197Z
Answers.LastActivityDate: 2022-01-17T13:41:15.197Z
Answers.UserDisplayName: Mike Jones
Answers.Body: <p>Some positions have clues which at least rule out certain openings, even if they don't identify one specific opening. For example, if a pawn is still at home, then the opening wasn't one in which that pawn moves or gets taken.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-17T10:24:34.237Z
Answers.LastActivityDate: 2022-01-17T10:24:34.237Z
Answers.UserDisplayName: Rosie F
Body: <p>I was watching Irina Krush's great <a href="https://youtu.be/tsqhaNHqvY0?t=1204" rel="nofollow noreferrer">lecture</a> on YouTube and, at 20:06, she asks &quot;Which opening is this position from?&quot; The answer is apparently the Sicilian, which made me wonder. How do you understand which middle game positions result from certain openings?</p>
  <p>In the video example, I am guessing that the absence of Black's c pawn and the fight against the d5 square may have given it away. But can't that be the result of a different opening as well? Also, can we reverse engineer <em>every</em> middle game position to an opening, or do some openings result in obvious middle game positions?</p>
  
Tags: <opening><middlegame><transpositions>
Title: How to understand which positions result from certain opening
ThreadText: # How to understand which positions result from certain opening
  
  (Asked by: username_0 on 2022-01-17)
  
  I was watching Irina Krush's great [lecture](https://youtu.be/tsqhaNHqvY0?t=1204) on YouTube and, at 20:06, she asks "Which opening is this position from?" The answer is apparently the Sicilian, which made me wonder. How do you understand which middle game positions result from certain openings?
  
  In the video example, I am guessing that the absence of Black's c pawn and the fight against the d5 square may have given it away. But can't that be the result of a different opening as well? Also, can we reverse engineer *every* middle game position to an opening, or do some openings result in obvious middle game positions?
  
  **Tags:** opening, middlegame, transpositions
  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_1 on 2022-01-17. Score: 6 | Accepted answer
  
  the absence of Black's C pawn and the fight against the D5 square
  
  That's more or less it. This kind of position is most probably the result of a Sicilian. Could it be something else? It can, but the Sicilian is the most likely opening.
  
  can we reverse engineer every middle game position to an opening
  
  No. This position for example is a middlegame with no clear signposts as to what opening led to it.
  [FEN "rn1r2k1/pp2qppp/8/8/3N2n1/1N2P3/P1Q2PPP/R4RK1 w - - 0 18"]
  
  Here's another example. It should be decently clear which opening this game began with. If not, imagine Black playing ...f5 and White taking with exf5.
  [FEN "r1bqk2r/pppn2bp/3p4/3Ppp2/2P5/2N1BP2/PP4PP/R2QKB1R w KQkq - 0 12"]
  
  > **Comments:**
  > **username_0**: That is exactly what I was asking for. AFAIU, more or less, some openings have more characteristics then other, leading to a more likely-to-see middle games :)  
  > **username_2**: Can someone clarify what should be the opening in the last, more clear example? Thanks.  
  > **username_1**: @DanielAlfredoSottile the second diagram is a [King's Indian](https://en.wikipedia.org/wiki/King%27s_Indian_Defence). From the classical variation diagram, White played d5, Black played ...f5, and there followed exf5 gxf5.  
  > **username_3**: The point of identifying the opening is that it should bring to mind the standard strategies that the opening leads to. Although the second diagram is certsinly "Kings-Indian-ish" it is far from being typical. Black has not castled and a pair of Knights have vanished through some nonstandard exchange. I would have great difficulty constructing a plausibe move sequence leading to this position and I do not see how to adapt much of my KI know-how.  
  > **username_1**: @PhilipRoe 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 e5 6. Nge2 Nc6 7. d5 Ne7 8. Ng3 Nd7 9. Be3 f5 10. exf5 Nxf5 11. Nxf5 gxf5  
  > **username_3**: @allure Thank you. Your reconstruction is very sensible and not as hard as I implied. Although It still doesnt ring many of my KI bells. Perhaps more thematic 8.Nc1 intending b4 Nb3 with a typical Q-side pus, against what will be a typical Black K-side push.  
  
  ---
  
  ### Answer by username_4 on 2022-01-17. Score: 2
  
  The biggest clue is the pawn structure. username_1's first diagram hints that is was a Grunfeld due to the queenside pawns. (Although since there are so many transpositions that the opening can change on a move's notice.) The further the game proceeds, the harder it becomes to guess the opening.
  
  As a teen, I played the Blackmar–Diemer Gambit, which had the trait of white missing the e and f pawns. However, black could transpose into the French or the Caro-Kann, making a d pawn into an e pawn opening.
  
  > **Comments:**
  > **username_1**: You sure the first diagram looks like a Grunfeld? It doesn't have ...g6.  
  
  ---
  
  ### Answer by username_5 on 2022-01-17. Score: 1
  
  Some positions have clues which at least rule out certain openings, even if they don't identify one specific opening. For example, if a pawn is still at home, then the opening wasn't one in which that pawn moves or gets taken.
  
  
  ---
  
  