Answers.Body: <p>Shannon estimated the number of possible positions roughly 10^43. This includes some illegal positions (e.g., pawns on the first rank, both kings in check) and excludes legal positions following captures and promotions. </p>
  
  <p>Taking these into account, Victor Allis calculated an upper bound of 5×10^52 for the number of positions, and estimated the true number to be about 10^50.</p>
  
  <p>Recent results improve that estimate, by proving an upper bound of only 2^155, which is less than 10^46.7 and showing an upper bound 2×10^40 in the absence of promotions.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-03T20:14:14.213Z
Answers.LastActivityDate: 2015-04-03T20:14:14.213Z
Answers.UserDisplayName: Chessbrain
Body: <p>How many possible positions are there in chess? Please be exact.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-04-03T23:58:29.563Z
Comments.Text: "Please be exact" = troll
Comments.UserDisplayName: Tony Ennis
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-08-10T14:21:54.770Z
Comments.Text: The number of legal chess positions is roughly 4x10^44: github.com/tromp/ChessPositionRanking
Comments.UserDisplayName: John Tromp
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-02T12:57:58.500Z
Comments.Text: To be more precise, it is about 4.8x10^44, as the latest research at https://github.com/tromp/ChessPositionRanking shows.
Comments.UserDisplayName: John Tromp
Tags: <theory><game-complexity>
Title: How many possible positions are there in chess?
ThreadText: # How many possible positions are there in chess?
  
  (Asked by: username_0 on 2015-04-03)
  
  How many possible positions are there in chess? Please be exact.
  
  **Tags:** theory, game-complexity
  
  > **Comments:**
  > **username_1**: "Please be exact" = troll  
  > **username_2**: The number of legal chess positions is roughly 4x10^44: github.com/tromp/ChessPositionRanking  
  > **username_2**: To be more precise, it is about 4.8x10^44, as the latest research at https://github.com/tromp/ChessPositionRanking shows.  
  
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  ## 1 answers
  
  ### Answer by username_3 on 2015-04-03. Score: 1
  
  Shannon estimated the number of possible positions roughly 10^43. This includes some illegal positions (e.g., pawns on the first rank, both kings in check) and excludes legal positions following captures and promotions.
  
  Taking these into account, Victor Allis calculated an upper bound of 5×10^52 for the number of positions, and estimated the true number to be about 10^50.
  
  Recent results improve that estimate, by proving an upper bound of only 2^155, which is less than 10^46.7 and showing an upper bound 2×10^40 in the absence of promotions.
  
  
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