Answers.Body: <blockquote>
  <p>Is there some authority that holds what the opening book is and updates it with classic games every year?</p>
  </blockquote>
  <p>No</p>
  <blockquote>
  <p>Or is it updated by the top positions and their win %?</p>
  </blockquote>
  <p>No</p>
  <blockquote>
  <p>when a pro player preps their out of book moves, they aren’t so much prepping out of book but things their opponent’s game history has never played before, correct?</p>
  </blockquote>
  <p>An &quot;out of book&quot; move is an opening novelty, a move which isn't known to theory. The current game between Caruana and van Foreest in the Tata Steel competition is a good example.</p>
  <pre><code>[Title &quot;Caruana - van Foreest, Tata Steel 2023&quot;]
  [Fen &quot;&quot;]
  [Startply &quot;14&quot;]
  
  1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be6 7. O-O f5 8. Qe2 Be7 9. Ne5 Nd7 10. Nxd7 Qxd7 11. f3 O-O 12. Bf4 Bf6 
  </code></pre>
  <p>Here is <a href="https://twitter.com/chess24com/status/1614977645296648192" rel="noreferrer">Chess24.com's tweet</a> on 7...f5 with a video clip of Peter Svidler's reaction:</p>
  <blockquote>
  <p>Jorden blitzes out 6...Be6 which is already an incredibly rare move ... I'm sure people have played it over the years ... but Be6 specifically in connection with the idea of playing f5 here is just very 2023.</p>
  </blockquote>
  <p>For me the shocking move is 11...O-O offering the knight on e4 as a piece sacrifice but not so much for the super GMs.</p>
  <p>Take a look at the timings from Chess24 for this part of the game:</p>
  <ol start="6">
  <li>Bd3  6s Be6 3s</li>
  <li>O-O  <strong>1m04s</strong> f5  9s</li>
  <li>Qe2  <strong>17m50s</strong> Be7  48s</li>
  <li>Ne5  <strong>7m17s</strong> Nd7 33s</li>
  <li>Nxd7  2m01s Qxd7  56s</li>
  <li>f3 2m33s O-O  <strong>4m08s</strong></li>
  <li>Bf4  <strong>5m39s</strong> Bf6  <strong>27m21s</strong></li>
  <li>c3  45s g5 18s</li>
  </ol>
  <p>So, for Caruana 6...Be6 is no big deal. He takes just over a minute for his reply. But 7...f5 is a real shock, just as it was for Svidler watching and commentating. It takes almost 18 minutes for him to work out a response. Then van Foreest takes just 48 seconds for 8...Be7 Looks like he had this position on his PC pre-game.</p>
  <p>Van Foreest thought for just over 4 minutes over the piece sacrifice 11...O-O but Caruana needed only 5 or 6 minutes to reject it with 12. Bf4. Now van Foreest is clearly out of his prep as he takes over 27 minutes to reply.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-17T06:25:08.167Z
Answers.Text: Makes sense. Out of book is a bit of a misnomer for out of prep. For people all studying the same prep, it means the same thing though. And then the literal usage of it on chess.com game reviews where it says "out of book on move 5", I'm curious what book exactly is it and how it updates. Aren't there tons of great moves that aren't in the official book these days?
Answers.UserDisplayName: SwimBikeRun
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-17T08:01:38.580Z
Answers.Text: "Is there some authority that holds what the opening book is and updates it with classic games every year?" > There kind of is though? One could argue that the various chess database providers are such an authority. There is more than one, but they don't substantially differ in their content. "out of book" very often does mean "not in the database of known games", and there are authorities that update the database. (and notably they also decide which games do enter the database)
Answers.UserDisplayName: blues
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-17T08:11:42.847Z
Answers.Text: Yeah I’m not satisfied with that aspect of the answer and would like to know more. Otherwise this answer was splendid on how one plays out of prep and how much time it costs them.
Answers.UserDisplayName: SwimBikeRun
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-16T17:18:22.700Z
Answers.LastActivityDate: 2023-01-16T17:18:22.700Z
Answers.UserDisplayName: Brian Towers
Answers.Body: <p>Getting someone &quot;out of the book&quot; just means to play an opening move they're not used to or that will require them to think by themselves rather than rely on theory.</p>
  <p>Just as today people will have analyzed different positions with different engines. In the past different people would have studied games from different sources. It's not an expression meant to be taken literally or with a &quot;strict&quot; sense, but rather as a way to say that a player is trying to avoid turning the game into a theoretical debate and just wants to &quot;play some chess&quot;.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-17T06:21:41.433Z
Answers.Text: Agreed. Okay I wasn't sure what to make of it when Chess.com says the move is out of book, even though I can look it up on Chess.com and see the lines off it that have been played thousands of times. Combined with the advice of "if you don't know openings, try to take your opponent out of book with principled play", I wasn't sure if I was missing anything to the term "out of book", or if it is used loosely and very context dependent on what your opponent's book is.
Answers.UserDisplayName: SwimBikeRun
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-17T07:37:56.537Z
Answers.Text: chess.com's automated analysis is mostly bait to make you buy a subscription. I'd ignore everything that isn't an evaluation number.
Answers.UserDisplayName: David
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-16T10:24:07.943Z
Answers.LastActivityDate: 2023-01-16T10:24:07.943Z
Answers.UserDisplayName: David
Body: <p>I see the phrase “getting out of the book” used in a way that no longer makes sense because if I’ve seen the position before then surely anyone good has seen it thousands of times, and it’s still in the book in terms of not throwing anyone off.</p>
  <p>Is there some authority that holds what the opening book is and updates it with classic games every year?</p>
  <p>Or is it updated by the top positions and their win %?</p>
  <p>A side question but related, when a pro player preps their out of book moves, they aren’t so much prepping out of book but things their opponent’s game history has never played before, correct?</p>
  
Tags: <opening>
Title: Is the concept “getting out of the book” outdated?
ThreadText: # Is the concept “getting out of the book” outdated?
  
  (Asked by: username_0 on 2023-01-16)
  
  I see the phrase “getting out of the book” used in a way that no longer makes sense because if I’ve seen the position before then surely anyone good has seen it thousands of times, and it’s still in the book in terms of not throwing anyone off.
  
  Is there some authority that holds what the opening book is and updates it with classic games every year?
  
  Or is it updated by the top positions and their win %?
  
  A side question but related, when a pro player preps their out of book moves, they aren’t so much prepping out of book but things their opponent’s game history has never played before, correct?
  
  **Tags:** opening
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2023-01-16. Score: 7
  
  > Is there some authority that holds what the opening book is and updates it with classic games every year?
  
  No
  
  > Or is it updated by the top positions and their win %?
  
  No
  
  > when a pro player preps their out of book moves, they aren’t so much prepping out of book but things their opponent’s game history has never played before, correct?
  
  An "out of book" move is an opening novelty, a move which isn't known to theory. The current game between Caruana and van Foreest in the Tata Steel competition is a good example.
  
  ```
  [Title "Caruana - van Foreest, Tata Steel 2023"]
  [Fen ""]
  [Startply "14"]
  
  1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be6 7. O-O f5 8. Qe2 Be7 9. Ne5 Nd7 10. Nxd7 Qxd7 11. f3 O-O 12. Bf4 Bf6 
  
  ```
  
  Here is [Chess24.com's tweet](https://twitter.com/chess24com/status/1614977645296648192) on 7...f5 with a video clip of Peter Svidler's reaction:
  
  > Jorden blitzes out 6...Be6 which is already an incredibly rare move ... I'm sure people have played it over the years ... but Be6 specifically in connection with the idea of playing f5 here is just very 2023.
  
  For me the shocking move is 11...O-O offering the knight on e4 as a piece sacrifice but not so much for the super GMs.
  
  Take a look at the timings from Chess24 for this part of the game:
  
  6. Bd3 6s Be6 3s
  7. O-O **1m04s** f5 9s
  8. Qe2 **17m50s** Be7 48s
  9. Ne5 **7m17s** Nd7 33s
  10. Nxd7 2m01s Qxd7 56s
  11. f3 2m33s O-O **4m08s**
  12. Bf4 **5m39s** Bf6 **27m21s**
  13. c3 45s g5 18s
  
  So, for Caruana 6...Be6 is no big deal. He takes just over a minute for his reply. But 7...f5 is a real shock, just as it was for Svidler watching and commentating. It takes almost 18 minutes for him to work out a response. Then van Foreest takes just 48 seconds for 8...Be7 Looks like he had this position on his PC pre-game.
  
  Van Foreest thought for just over 4 minutes over the piece sacrifice 11...O-O but Caruana needed only 5 or 6 minutes to reject it with 12. Bf4. Now van Foreest is clearly out of his prep as he takes over 27 minutes to reply.
  
  > **Comments:**
  > **username_0**: Makes sense. Out of book is a bit of a misnomer for out of prep. For people all studying the same prep, it means the same thing though. And then the literal usage of it on chess.com game reviews where it says "out of book on move 5", I'm curious what book exactly is it and how it updates. Aren't there tons of great moves that aren't in the official book these days?  
  > **username_2**: "Is there some authority that holds what the opening book is and updates it with classic games every year?" > There kind of is though? One could argue that the various chess database providers are such an authority. There is more than one, but they don't substantially differ in their content. "out of book" very often does mean "not in the database of known games", and there are authorities that update the database. (and notably they also decide which games do enter the database)  
  > **username_0**: Yeah I’m not satisfied with that aspect of the answer and would like to know more. Otherwise this answer was splendid on how one plays out of prep and how much time it costs them.  
  
  ---
  
  ### Answer by username_3 on 2023-01-16. Score: 4
  
  Getting someone "out of the book" just means to play an opening move they're not used to or that will require them to think by themselves rather than rely on theory.
  
  Just as today people will have analyzed different positions with different engines. In the past different people would have studied games from different sources. It's not an expression meant to be taken literally or with a "strict" sense, but rather as a way to say that a player is trying to avoid turning the game into a theoretical debate and just wants to "play some chess".
  
  > **Comments:**
  > **username_0**: Agreed. Okay I wasn't sure what to make of it when Chess.com says the move is out of book, even though I can look it up on Chess.com and see the lines off it that have been played thousands of times. Combined with the advice of "if you don't know openings, try to take your opponent out of book with principled play", I wasn't sure if I was missing anything to the term "out of book", or if it is used loosely and very context dependent on what your opponent's book is.  
  > **username_3**: chess.com's automated analysis is mostly bait to make you buy a subscription. I'd ignore everything that isn't an evaluation number.  
  
  ---
  
  