Answers.Body: <p>It means that there is no explicit coding of action choices to promote to queen, it is the default assumption if the underpromotion actions are not taken.</p>
  
  <p>The Alpha Zero chess implementation can represent promotion to queen by not selecting an underpromotion action, whilst moving a pawn so that it qualifies for promotion.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-08-12T20:13:49.117Z
Answers.LastActivityDate: 2019-08-12T20:13:49.117Z
Answers.UserDisplayName: Neil Slater
Body: <p>"The final 9 planes encode possible underpromotions for pawn moves or captures in two possible diagonals, to knight, bishop or rook  respectively.   Other  pawn  moves  or  captures  from  the  seventh  rank  are  promoted  to  a queen." 
  Doesn't this mean that the network does not know that it can promote to a queen?</p>
  
Tags: <neural-networks><chess><alphazero><deepmind>
Title: Alpha Zero queen promotion
UserDisplayName: Bojidar Ivanov
ThreadText: # Alpha Zero queen promotion
  
  (Asked by: username_0 on 2019-08-12)
  
  "The final 9 planes encode possible underpromotions for pawn moves or captures in two possible diagonals, to knight, bishop or rook respectively. Other pawn moves or captures from the seventh rank are promoted to a queen."
  Doesn't this mean that the network does not know that it can promote to a queen?
  
  **Tags:** neural-networks, chess, alphazero, deepmind
  
  
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  ## 1 answers
  
  ### Answer by username_1 on 2019-08-12. Score: 3
  
  It means that there is no explicit coding of action choices to promote to queen, it is the default assumption if the underpromotion actions are not taken.
  
  The Alpha Zero chess implementation can represent promotion to queen by not selecting an underpromotion action, whilst moving a pawn so that it qualifies for promotion.
  
  
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