Answers.Body: <p>For easier visualization, I recommend this video:
  <a href="https://twitter.com/i/status/1257053365424578565" rel="nofollow noreferrer">https://twitter.com/i/status/1257053365424578565</a></p>
  <p>The more detailed article about GO algorithms:
  <a href="https://deepmind.com/blog/article/alphago-zero-starting-scratch" rel="nofollow noreferrer">https://deepmind.com/blog/article/alphago-zero-starting-scratch</a>.</p>
  <p>With its breadth of <span class="math-container">$250$</span> possible moves each turn (go is played on a <span class="math-container">$19$</span> by <span class="math-container">$19$</span> board, compared to the much smaller <span class="math-container">$8$</span> by <span class="math-container">$8$</span> chess field) and a typical game depth of <span class="math-container">$150$</span> moves, there are about <span class="math-container">$250^{150}$</span>, or
  <span class="math-container">$10^{360}$</span>.</p>
  <p>After <span class="math-container">$2$</span> moves in go, it's <span class="math-container">$130000$</span> possible combinations.</p>
  <p><strong>Decision tree pruning</strong></p>
  <p><a href="https://i.sstatic.net/bR68K.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/bR68K.png" alt="enter image description here" /></a></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-09-21T19:45:08.893Z
Answers.Text: Do you know the approximate depth or the average depth?
Answers.UserDisplayName: High GPA
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-09-22T12:31:07.760Z
Answers.Text: if it'll be Monte Carlo Tree Search - then hypothesizes 3-5 deepth or 5-15 (with prunning) (depend on CPU, GPU)
Answers.UserDisplayName: Piotr Żak
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-09-21T10:28:19.150Z
Answers.LastActivityDate: 2020-09-22T16:50:42.370Z
Answers.LastEditDate: 2020-09-22T16:50:42.370Z
Answers.UserDisplayName: Piotr Żak
Body: <p>I cannot find reliable sources but someone says it is 40 moves and someone else says it is 50+ moves. I read their papers and they use value function (NN) and policy function to trim the tree, so more layers can be searched while spending less time searching less different positions.</p>
  <p>My question is, is the search depth a fixed preset parameter? If so, approximately how much is it back to 2016 (AlphaGo) and 2018 (AlphaGo Zero)?</p>
  
Tags: <neural-networks><reinforcement-learning><monte-carlo-tree-search><alphago-zero><alphago>
Title: What is the search depth of AlphaGo and AlphaGo Zero?
UserDisplayName: High GPA
ThreadText: # What is the search depth of AlphaGo and AlphaGo Zero?
  
  (Asked by: username_0 on 2020-09-19)
  
  I cannot find reliable sources but someone says it is 40 moves and someone else says it is 50+ moves. I read their papers and they use value function (NN) and policy function to trim the tree, so more layers can be searched while spending less time searching less different positions.
  
  My question is, is the search depth a fixed preset parameter? If so, approximately how much is it back to 2016 (AlphaGo) and 2018 (AlphaGo Zero)?
  
  **Tags:** neural-networks, reinforcement-learning, monte-carlo-tree-search, alphago-zero, alphago
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2020-09-21. Score: 1
  
  For easier visualization, I recommend this video:
  <https://twitter.com/i/status/1257053365424578565>
  
  The more detailed article about GO algorithms:
  <https://deepmind.com/blog/article/alphago-zero-starting-scratch>.
  
  With its breadth of $250$ possible moves each turn (go is played on a $19$ by $19$ board, compared to the much smaller $8$ by $8$ chess field) and a typical game depth of $150$ moves, there are about $250^{150}$, or
  $10^{360}$.
  
  After $2$ moves in go, it's $130000$ possible combinations.
  
  **Decision tree pruning**
  
  [![enter image description here](https://i.sstatic.net/bR68K.png)](https://i.sstatic.net/bR68K.png)
  
  > **Comments:**
  > **username_0**: Do you know the approximate depth or the average depth?  
  > **username_1**: if it'll be Monte Carlo Tree Search - then hypothesizes 3-5 deepth or 5-15 (with prunning) (depend on CPU, GPU)  
  
  ---
  
  