Answers.Body: <p>I found an answer. After spending a few hours digging through PGN-Extract's website I found this:</p>
  <p><code>* b6</code></p>
  <p>means that you are interested in all games in which Black replied 1 ... b6 regardless of White's first move. The sequence:</p>
  <p><code>d4 * c4 * Nc3 *</code></p>
  <p>will pick up Nimzo-Indian, Grunfeld, King's Indian, etc. defenses. This notation is not possible with positional variations</p>
  <p>Edit:
  You put the above text in a file and then set it as a parameter when calling pgn-extract like this:</p>
  <p><code>pgn-extract -v[file that contains the rules]</code></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-27T07:42:49.830Z
Answers.Text: Sorry it took you several hours to find it in the documentation I wrote for pgn-extract! The documentation has tended to grow slightly chaotically over the years as each new feature was added but I would be happy to receive suggestions for how it could be improved.
Answers.UserDisplayName: kentdjb
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-27T15:14:58.153Z
Answers.Text: For reference, you can find pgn-extract at [Inline Link] (https://www.cs.kent.ac.uk/~djb/pgn-extract/) It's free and open source.
Answers.UserDisplayName: kentdjb
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-27T20:52:56.163Z
Answers.Text: @kentdjb I would suggest rewording the index/table of contents to be more concise and intuitive. 
  For example, the two entries in this [image](https://imgur.com/c13909e) can be combined and shortened into "Matching by FEN"
  And another [four entries](https://imgur.com/pwWy8ux) could be shortened into "Matching by Game Result". This makes finding what you need from the index much easier and less daunting because you're not just looking at a giant wall of text.
Answers.UserDisplayName: SimonUnderwood
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-27T21:26:33.180Z
Answers.Text: Simon: thanks for those suggestions. I will aim to do some revision. I have also been thinking that it would be good to have a section of typical use cases for ease of reference.
Answers.UserDisplayName: kentdjb
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-27T04:20:50.497Z
Answers.LastActivityDate: 2021-12-27T04:20:50.497Z
Answers.UserDisplayName: SimonUnderwood
Body: <p>I want to filter a PGN database for games where one side plays a series of moves but I don't care what the other side does during that sequence. For example the bongcloud is where one side plays 1. e3 ... 2. Ke2. (I know there are lots of variations but that's ignore that for now). I don't really care what black does on turn one or two. How would I filter for that? I don't want to list out all the moves black can make and then input 20+ parameters. Is there a simpler way to achieve this?</p>
  
Tags: <opening><database><pgn>
Title: Filter PGN for games for one sided openings
ThreadText: # Filter PGN for games for one sided openings
  
  (Asked by: username_0 on 2021-12-27)
  
  I want to filter a PGN database for games where one side plays a series of moves but I don't care what the other side does during that sequence. For example the bongcloud is where one side plays 1. e3 ... 2. Ke2. (I know there are lots of variations but that's ignore that for now). I don't really care what black does on turn one or two. How would I filter for that? I don't want to list out all the moves black can make and then input 20+ parameters. Is there a simpler way to achieve this?
  
  **Tags:** opening, database, pgn
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2021-12-27. Score: 2 | Accepted answer
  
  I found an answer. After spending a few hours digging through PGN-Extract's website I found this:
  
  `* b6`
  
  means that you are interested in all games in which Black replied 1 ... b6 regardless of White's first move. The sequence:
  
  `d4 * c4 * Nc3 *`
  
  will pick up Nimzo-Indian, Grunfeld, King's Indian, etc. defenses. This notation is not possible with positional variations
  
  Edit:
  You put the above text in a file and then set it as a parameter when calling pgn-extract like this:
  
  `pgn-extract -v[file that contains the rules]`
  
  > **Comments:**
  > **username_1**: Sorry it took you several hours to find it in the documentation I wrote for pgn-extract! The documentation has tended to grow slightly chaotically over the years as each new feature was added but I would be happy to receive suggestions for how it could be improved.  
  > **username_1**: For reference, you can find pgn-extract at [Inline Link] (https://www.cs.kent.ac.uk/~djb/pgn-extract/) It's free and open source.  
  > **username_0**: @username_1 I would suggest rewording the index/table of contents to be more concise and intuitive.  For example, the two entries in this [image](https://imgur.com/c13909e) can be combined and shortened into "Matching by FEN" And another [four entries](https://imgur.com/pwWy8ux) could be shortened into "Matching by Game Result". This makes finding what you need from the index much easier and less daunting because you're not just looking at a giant wall of text.  
  > **username_1**: Simon: thanks for those suggestions. I will aim to do some revision. I have also been thinking that it would be good to have a section of typical use cases for ease of reference.  
  
  ---
  
  