Answers.Body: <p>Your evaluation as <strong>black</strong> being much better seems to be correct. However, I would argue that neither of the evaluations you provided is accurate.</p>
  <p>As for the <strong>chess.com</strong> evaluation, I think your result is incorrect due to a network/server error of some sort because I can't seem to reproduce your results (Edit: Discrepancy in result is due to game being drawn at this position as OP has clarified in comments). Here's my result of chess.com's engine at <strong>depth = 20 using Stockfish 16.1 Lite</strong>: <code>(-3.43)</code></p>
  <p><a href="https://i.sstatic.net/AJdvpGG8.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/AJdvpGG8.png" alt="Chess.com evaluation of position" /></a></p>
  <p>For <strong>Chessvision</strong>, using the Chrome extension, I got <code>-6.2</code> for this position using <strong>Stockfish HCE at depth 20</strong> (which is similar to your reported evaluation of <code>-5.9</code>)</p>
  <p><a href="https://i.sstatic.net/QSZ8UATn.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/QSZ8UATn.png" alt="Chessvision evaluation of position" /></a></p>
  <p>To compare these results, let us consider few more evaluations: <em>(click on the image to view in full size)</em></p>
  <ul>
  <li>Lichess <strong>stockfish 11 using HCE</strong> gave the evaluation of <code>-6.8</code> at <strong>depth = 20</strong>.</li>
  </ul>
  <p><a href="https://i.sstatic.net/YjtniN8x.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/YjtniN8xs.png" alt="Lichess evaluation using HCE" /></a></p>
  <ul>
  <li>Lichess <strong>stockfish 16 using NNUE</strong> gave the evaluation of <code>-3.5</code> at <strong>depth = 20</strong>.</li>
  </ul>
  <p><a href="https://i.sstatic.net/YjD9wvsx.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/YjD9wvsxs.png" alt="Lichess evaluation using NNUE at depth 20" /></a></p>
  <ul>
  <li>And finally, Lichess <strong>stockfish 16 using NNUE</strong> gave the evaluation of <code>-4.0</code> at <strong>depth = 30</strong></li>
  </ul>
  <p><a href="https://i.sstatic.net/LhsXx5Wd.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/LhsXx5Wds.png" alt="Lichess evaluation using NNUE at depth 30" /></a></p>
  <p>In order to understand the reason for difference in these evaluations, one must know the difference between Stockfish HCE, Stockfish NNUE and Stockfish Lite.</p>
  <p><strong>Stockfish HCE</strong> was basically using <a href="https://en.wikipedia.org/wiki/Evaluation_function#Handcrafted_evaluation_functions" rel="nofollow noreferrer">handcrafted evaluation functions</a> to evaluate a given position and did not actively learn from games played in similar positions. See <a href="https://chess.stackexchange.com/questions/45972/why-does-this-quiet-position-with-material-in-whites-favour-not-favour-white">this</a> recent question to understand the pitfalls of handcrafted evaluation.</p>
  <p>Then came <strong>Stockfish NNUE</strong> (<a href="https://en.wikipedia.org/wiki/Efficiently_updatable_neural_network" rel="nofollow noreferrer">Efficiently Updatable Neural Network</a> in reverse) which use neural nets to add learning capability to the above handcrafted evaluation function. <strong>Introduction of NNUE has made HCE model obsolete</strong> (<a href="https://github.com/official-stockfish/Stockfish/commit/af110e02ec96cdb46cf84c68252a1da15a902395" rel="nofollow noreferrer">Since July 2023, HCE model has been removed by Stockfish</a>)</p>
  <p>Finally, chess.com's <strong>Stockfish Lite</strong> is in the process of transitioning from HCE model to smaller NNUEs. (<a href="https://support.chess.com/en/articles/9462780-chess-engines-on-chess-com-how-do-they-work" rel="nofollow noreferrer">link</a>)</p>
  <p>Hence, the <strong>most accurate</strong> engine evaluations among all of the above at this point in time would be <strong>Stockfish 16 using NNUE at depths 20 <code>(-3.5)</code> and 30 <code>(-4.0)</code></strong>.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-07-31T21:56:57.493Z
Answers.LastActivityDate: 2024-08-01T08:20:17.380Z
Answers.LastEditDate: 2024-08-01T08:20:17.380Z
Answers.UserDisplayName: Rishav Raj
Body: <p>For this position, the eval bar on Chess.com (Stockfish 16.1 Lite, depth=20) says it's equal (image below).</p>
  <p>I couldn't understand why (also, it's an anonymous game, so I don't have the analysis), so I used ChessVision (Stockfish (not sure what version), depth=20), and it says it's -5.9, and it seems correct (image below).</p>
  <p>Why might Chess.com evaluate this as equal?</p>
  <pre><code>    [Title &quot;White to move&quot;]
      [FEN &quot;1r1qk1nr/p2n1ppb/P3p2p/1QppP2P/Rb3PP1/2N1B3/2P5/1N2KB1R w Kk - 0 1&quot;]
  </code></pre>
  <p>Chess.com:<br />
  <a href="https://i.sstatic.net/UDdk6nIE.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/UDdk6nIE.png" alt="enter image description here" /></a></p>
  <p>ChessVision:<br />
  <a href="https://i.sstatic.net/oTZcCNDA.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/oTZcCNDA.png" alt="enter image description here" /></a></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-31T22:59:18.890Z
Comments.Text: Could it be that the game was drawn by triple repetition (or that White's coming Qe2 would complete a triple repetition), and the evaluation took this into account?
Comments.UserDisplayName: Noam D. Elkies
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-07-31T23:22:53.673Z
Comments.Text: @NoamD.Elkies the game was indeed drawn by triple repetition. So you think that's the reason for this eval bar? I actually "manually" analyzed my (anonymous) game by continuing it in various ways and jumped back and forth between positions, but every time i got back to the original ending position, the eval bar moved to 0.0. I hadn't realized that's what happens, I'd say it's an unexpected behavior, but so be it. Thanks!
Comments.UserDisplayName: OfirD
Tags: <stockfish>
Title: Position evaluated as equal although it doesn't seem like it
ThreadText: # Position evaluated as equal although it doesn't seem like it
  
  (Asked by: username_0 on 2024-07-31)
  
  For this position, the eval bar on Chess.com (Stockfish 16.1 Lite, depth=20) says it's equal (image below).
  I couldn't understand why (also, it's an anonymous game, so I don't have the analysis), so I used ChessVision (Stockfish (not sure what version), depth=20), and it says it's -5.9, and it seems correct (image below).
  Why might Chess.com evaluate this as equal?
      [Title "White to move"]
      [FEN "1r1qk1nr/p2n1ppb/P3p2p/1QppP2P/Rb3PP1/2N1B3/2P5/1N2KB1R w Kk - 0 1"]
  
  Chess.com:
  
  ChessVision:
  
  **Tags:** stockfish
  
  > **Comments:**
  > **username_1**: Could it be that the game was drawn by triple repetition (or that White's coming Qe2 would complete a triple repetition), and the evaluation took this into account?  
  > **username_0**: @NoamD.Elkies the game was indeed drawn by triple repetition. So you think that's the reason for this eval bar? I actually "manually" analyzed my (anonymous) game by continuing it in various ways and jumped back and forth between positions, but every time i got back to the original ending position, the eval bar moved to 0.0. I hadn't realized that's what happens, I'd say it's an unexpected behavior, but so be it. Thanks!  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2024-07-31. Score: 1
  
  Your evaluation as **black** being much better seems to be correct. However, I would argue that neither of the evaluations you provided is accurate.
  
  As for the **chess.com** evaluation, I think your result is incorrect due to a network/server error of some sort because I can't seem to reproduce your results (Edit: Discrepancy in result is due to game being drawn at this position as OP has clarified in comments). Here's my result of chess.com's engine at **depth = 20 using Stockfish 16.1 Lite**: `(-3.43)`
  
  [![Chess.com evaluation of position](https://i.sstatic.net/AJdvpGG8.png)](https://i.sstatic.net/AJdvpGG8.png)
  
  For **Chessvision**, using the Chrome extension, I got `-6.2` for this position using **Stockfish HCE at depth 20** (which is similar to your reported evaluation of `-5.9`)
  
  [![Chessvision evaluation of position](https://i.sstatic.net/QSZ8UATn.png)](https://i.sstatic.net/QSZ8UATn.png)
  
  To compare these results, let us consider few more evaluations: *(click on the image to view in full size)*
  
  * Lichess **stockfish 11 using HCE** gave the evaluation of `-6.8` at **depth = 20**.
  
  [![Lichess evaluation using HCE](https://i.sstatic.net/YjtniN8xs.png)](https://i.sstatic.net/YjtniN8x.png)
  
  * Lichess **stockfish 16 using NNUE** gave the evaluation of `-3.5` at **depth = 20**.
  
  [![Lichess evaluation using NNUE at depth 20](https://i.sstatic.net/YjD9wvsxs.png)](https://i.sstatic.net/YjD9wvsx.png)
  
  * And finally, Lichess **stockfish 16 using NNUE** gave the evaluation of `-4.0` at **depth = 30**
  
  [![Lichess evaluation using NNUE at depth 30](https://i.sstatic.net/LhsXx5Wds.png)](https://i.sstatic.net/LhsXx5Wd.png)
  
  In order to understand the reason for difference in these evaluations, one must know the difference between Stockfish HCE, Stockfish NNUE and Stockfish Lite.
  
  **Stockfish HCE** was basically using [handcrafted evaluation functions](https://en.wikipedia.org/wiki/Evaluation_function#Handcrafted_evaluation_functions) to evaluate a given position and did not actively learn from games played in similar positions. See [this](https://chess.stackexchange.com/questions/45972/why-does-this-quiet-position-with-material-in-whites-favour-not-favour-white) recent question to understand the pitfalls of handcrafted evaluation.
  
  Then came **Stockfish NNUE** ([Efficiently Updatable Neural Network](https://en.wikipedia.org/wiki/Efficiently_updatable_neural_network) in reverse) which use neural nets to add learning capability to the above handcrafted evaluation function. **Introduction of NNUE has made HCE model obsolete** ([Since July 2023, HCE model has been removed by Stockfish](https://github.com/official-stockfish/Stockfish/commit/af110e02ec96cdb46cf84c68252a1da15a902395))
  
  Finally, chess.com's **Stockfish Lite** is in the process of transitioning from HCE model to smaller NNUEs. ([link](https://support.chess.com/en/articles/9462780-chess-engines-on-chess-com-how-do-they-work))
  
  Hence, the **most accurate** engine evaluations among all of the above at this point in time would be **Stockfish 16 using NNUE at depths 20 `(-3.5)` and 30 `(-4.0)`**.
  
  
  ---
  
  