Answers.Body: <p>The Stockfish version that played agaist AlphaZero was significantly compromised in several different aspects:</p>
  
  <ol>
  <li>There was no opening book available</li>
  <li>Time control was 1 minute/move, which throws out of the window various optimizations re: using more time thinking about difficult moves</li>
  <li>Stockfish had <code>threads=64</code> set, but the actual hardware had only 8 CPU cores, that effectively slowed things down quite a lot</li>
  <li>The hardware was quite different -- an average $1k PC (Stockfish) against a bunch of specialized hardware that might cost millions and is not accessible to anyone</li>
  <li>There are more, but these are main points.</li>
  </ol>
  
  <p>Answering your question, there's no way to measure how much rating Stockfish had in a very handicapped conditions it had to run.</p>
  
  <p>Nonetheless, winning over Stockfish is quite an achievement, no matter how handicapped it was and how much was the difference in hardware cost.</p>
  
  <hr>
  
  <p>UPDATE: in the recent article <a href="https://deepmind.com/blog/alphazero-shedding-new-light-grand-games-chess-shogi-and-go/" rel="nofollow noreferrer">"AlphaZero: Shedding new light on the grand games of chess, shogi and Go"</a> the rating for Stockfish was drawn as a line at <strong>3500</strong>. Besides that, the article provides the new games played with a reasonable time control for SF as well as opening books.</p>
  
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Answers.CreationDate: 2018-06-24T06:02:35.240Z
Answers.Text: @THN a quick google search came out with this: https://www.reddit.com/r/chess/comments/7igro1/alphazero_reactions_from_top_gms_stockfish_author/  I'll post the link where 8 CPU cores are mentioned later, if I find it.
Answers.UserDisplayName: lenik
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Answers.LastActivityDate: 2018-12-13T07:02:11.823Z
Answers.LastEditDate: 2018-12-13T07:02:11.823Z
Answers.UserDisplayName: lenik
Answers.Body: <p>AlphaZero vs. Stockfish 8, 1000-game match as in <a href="http://science.sciencemag.org/content/362/6419/1140.full" rel="nofollow noreferrer">the latest paper</a> (with Stockfish operating at full power) yielded a score of +155 -6 =839. Using <a href="http://www.3dkingdoms.com/chess/elo.htm" rel="nofollow noreferrer">this calculator</a> gives an elo difference of 52.</p>
  
  <p>Stockfish 8's elo rating on computer chess rating lists is <a href="http://www.computerchess.org.uk/ccrl/4040/rating_list_all.html" rel="nofollow noreferrer">about 3378</a>, giving AlphaZero a rating of about 3430.</p>
  
  <p>Disclaimer: these rating lists are generated with hundreds of thousands of games between all the engines. With only 1000 games against a single engine, this 3430 rating is unlikely to be accurate. AlphaZero is certainly one of the stronger engines out there, but it's not clear exactly how strong.</p>
  
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Answers.UserDisplayName: Allure
Body: <p>AlphaZero has defeated Stockfish with all novelties and brilliant strategic sacrifices. But some people were disputing its win, because Stockfish was running on weak hardware (1 GB RAM), not access to opening book, not having free time control, maybe not have endgame table base, etc.</p>
  <p>This setting by DeepMind is understandable from a scientific perspective though. It is to test intuitive/strategic play by deep learning technique vs. counting/tactical play by brute force search. However, this leaves chess lovers with many questions like what is the true strength of AlphaZero? What is the true advantage of strategic/positional sacrifice play? Were Morphy, Tal, and others correct and Stockfish wrong? Or full version Stockfish is still the best?</p>
  <p>One work around is to replicate the Stockfish version that played AlphaZero, to see how strong it is compared to the full version and other engine and human. Thus we could infer the Elo rating of AlphaZero and answer most questions.</p>
  <p>So, did anyone test it? Is anyone interested in testing it? Maybe Stockfish developers, because Stockfish's pride is at stake? Or is there other way to approach the problem?</p>
  <p>Thanks</p>
  <p>Edit:</p>
  <ul>
  <li>Note that Stockfish had good 64 threads CPU and could evaluate 70 million positions/second.</li>
  <li>The Stockfish Elo rating provided in the paper is the full version, thus this replication is needed.</li>
  <li><a href="https://arxiv.org/abs/1712.01815" rel="nofollow noreferrer">The paper</a>.</li>
  </ul>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-03-17T12:35:35.383Z
Comments.Text: You are not going to find a (human) Elo rating for stockfish. The best you can hope for is a computer Elo rating determined from many games between various computer engines. Even then, I am not sure what this would tell about the rating of AlphaZero, because AlphaZero only played against some version of stockfish and not against any of the other computer engines in the pool.
Comments.UserDisplayName: user1583209
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Comments.CreationDate: 2018-03-17T13:55:16.437Z
Comments.Text: @THN You won't find any reliable human rating for Stockfish.
Comments.UserDisplayName: SmallChess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-06-23T19:45:03.977Z
Comments.Text: The suggestion is made that Stockfish cannot reliably be rated against humans. I read suggestions like this often (often coupled with suggestions—equally false—that online and federation ratings cannot be correlated). I believe the suggestion to be a canard. As far as a I know, nothing statistically prevents a reasonably accurate rating of computers on an extrapolated human scale.
Comments.UserDisplayName: thb
Tags: <engines><strategy><stockfish><alphazero><hardware>
Title: What is the Elo rating of Stockfish version that played AlphaZero?
ThreadText: # What is the Elo rating of Stockfish version that played AlphaZero?
  
  (Asked by: username_0 on 2018-03-17)
  
  AlphaZero has defeated Stockfish with all novelties and brilliant strategic sacrifices. But some people were disputing its win, because Stockfish was running on weak hardware (1 GB RAM), not access to opening book, not having free time control, maybe not have endgame table base, etc.
  
  This setting by DeepMind is understandable from a scientific perspective though. It is to test intuitive/strategic play by deep learning technique vs. counting/tactical play by brute force search. However, this leaves chess lovers with many questions like what is the true strength of AlphaZero? What is the true advantage of strategic/positional sacrifice play? Were Morphy, Tal, and others correct and Stockfish wrong? Or full version Stockfish is still the best?
  
  One work around is to replicate the Stockfish version that played AlphaZero, to see how strong it is compared to the full version and other engine and human. Thus we could infer the Elo rating of AlphaZero and answer most questions.
  
  So, did anyone test it? Is anyone interested in testing it? Maybe Stockfish developers, because Stockfish's pride is at stake? Or is there other way to approach the problem?
  
  Thanks
  
  Edit:
  
  * Note that Stockfish had good 64 threads CPU and could evaluate 70 million positions/second.
  * The Stockfish Elo rating provided in the paper is the full version, thus this replication is needed.
  * [The paper](https://arxiv.org/abs/1712.01815).
  
  **Tags:** engines, strategy, stockfish, alphazero, hardware
  
  > **Comments:**
  > **username_1**: You are not going to find a (human) Elo rating for stockfish. The best you can hope for is a computer Elo rating determined from many games between various computer engines. Even then, I am not sure what this would tell about the rating of AlphaZero, because AlphaZero only played against some version of stockfish and not against any of the other computer engines in the pool.  
  > **username_2**: @username_0 You won't find any reliable human rating for Stockfish.  
  > **username_3**: The suggestion is made that Stockfish cannot reliably be rated against humans. I read suggestions like this often (often coupled with suggestions—equally false—that online and federation ratings cannot be correlated). I believe the suggestion to be a canard. As far as a I know, nothing statistically prevents a reasonably accurate rating of computers on an extrapolated human scale.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_4 on 2018-06-23. Score: 4
  
  The Stockfish version that played agaist AlphaZero was significantly compromised in several different aspects:
  
  1. There was no opening book available
  2. Time control was 1 minute/move, which throws out of the window various optimizations re: using more time thinking about difficult moves
  3. Stockfish had `threads=64` set, but the actual hardware had only 8 CPU cores, that effectively slowed things down quite a lot
  4. The hardware was quite different -- an average $1k PC (Stockfish) against a bunch of specialized hardware that might cost millions and is not accessible to anyone
  5. There are more, but these are main points.
  
  Answering your question, there's no way to measure how much rating Stockfish had in a very handicapped conditions it had to run.
  
  Nonetheless, winning over Stockfish is quite an achievement, no matter how handicapped it was and how much was the difference in hardware cost.
  
  ---
  
  UPDATE: in the recent article ["AlphaZero: Shedding new light on the grand games of chess, shogi and Go"](https://deepmind.com/blog/alphazero-shedding-new-light-grand-games-chess-shogi-and-go/) the rating for Stockfish was drawn as a line at **3500**. Besides that, the article provides the new games played with a reasonable time control for SF as well as opening books.
  
  > **Comments:**
  > **username_4**: @username_0 a quick google search came out with this: https://www.reddit.com/r/chess/comments/7igro1/alphazero_reactions_from_top_gms_stockfish_author/  I'll post the link where 8 CPU cores are mentioned later, if I find it.  
  
  ---
  
  ### Answer by username_5 on 2018-12-13. Score: 3
  
  AlphaZero vs. Stockfish 8, 1000-game match as in [the latest paper](http://science.sciencemag.org/content/362/6419/1140.full) (with Stockfish operating at full power) yielded a score of +155 -6 =839. Using [this calculator](http://www.3dkingdoms.com/chess/elo.htm) gives an elo difference of 52.
  
  Stockfish 8's elo rating on computer chess rating lists is [about 3378](http://www.computerchess.org.uk/ccrl/4040/rating_list_all.html), giving AlphaZero a rating of about 3430.
  
  Disclaimer: these rating lists are generated with hundreds of thousands of games between all the engines. With only 1000 games against a single engine, this 3430 rating is unlikely to be accurate. AlphaZero is certainly one of the stronger engines out there, but it's not clear exactly how strong.
  
  
  ---
  
  