Answers.Body: <p>Yes, it is a bug. I just plugged that updated position into Stockfish 10 running on a quad-core 2.9 GHz laptop, and it is still over +5.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T12:45:50.297Z
Answers.Text: Still have not had time, but I will. We have had company coming this week for 10 days, and I am in the middle of a major email migration for a customer.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T12:43:54.953Z
Answers.LastActivityDate: 2019-10-11T12:45:33.957Z
Answers.LastEditDate: 2019-10-11T12:45:33.957Z
Answers.UserDisplayName: PhishMaster
Answers.Body: <p>This is <strong>not</strong> a missed win for black, both <code>Kb6</code> and <code>Kb7</code> are equally <strong>losing for black</strong> as you are simply a full rook down without any real compensation. <code>Qe3</code> move simply stops black's only way to breakthrough as it stops <code>Bxh3.</code> That is not white's only move either, <code>Kh1</code> and <code>Rc3</code> (though walks in the way of the knight) are sufficiently good for white too.</p>
  
  <p>So either: </p>
  
  <ul>
  <li><p>The cloud engine didn't get to run sufficiently long and gave a wrong evaluation, or</p></li>
  <li><p>you simply mis-read or mis-interpreted the evaluation of the engine, or </p></li>
  <li><p>you're showing us the wrong position here.</p></li>
  </ul>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T12:43:19.073Z
Answers.Text: Thanks for your answer. I have updated my question which points to your first suggestion. I've since changed the settings from '10 seconds' to 'Unlimited' and increased lines to the maximum (5) from 3, and it still gives the same suggestion. Is there a way I can report this to chess.com as a bug then?
Answers.UserDisplayName: Darren H
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T12:53:58.690Z
Answers.Text: @DarrenH Yeah both the textual and numerical evals are wrong, because probably the algorithm uses a very short ponder time for the engine to evaluate when parsing the whole game and in the `Kb7` line as you see its evaluation stems from a `depth 1` calculation, hence it's completely unreliable. You can report these things of course, try bottom left of your screen there's a help icon, once you click a "report bug" option should appear. For analysing your games with an engine, it's much simpler to just copy your game or its FEN to lichess (among others) and analyse there, all features are free.
Answers.UserDisplayName: Ellie
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T12:56:44.073Z
Answers.Text: Black may have a slim chance for counterplay if White does not play precisely
Answers.UserDisplayName: David
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T13:18:21.160Z
Answers.Text: So the takeaway here then is to use Lichess rather than Chess.com. Do they use different software? Why is Lichess better?
Answers.UserDisplayName: Darren H
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T13:19:20.947Z
Answers.Text: @David yes that was what I was hoping for, unfortunately we were both playing pretty badly that day, but it seems my opponent wasn't playing badly enough!
Answers.UserDisplayName: Darren H
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T14:30:12.737Z
Answers.Text: @DarrenH no! the takeaway here should be that both `Kb6` and `Kb7` are losing since that's what your question was. Now whether you wanna use lichess.org or chess.com is entirely up to you, I just gave you a practical recommendation.
Answers.UserDisplayName: Ellie
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-14T06:21:32.847Z
Answers.Text: @DarrenH The takeaway is to not use software at all. You (hopefully) have grey matter on your brain. That's your chess engine!
Answers.UserDisplayName: David
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-10-11T11:30:12.590Z
Answers.LastActivityDate: 2019-10-11T11:45:02.257Z
Answers.LastEditDate: 2019-10-11T11:45:02.257Z
Answers.UserDisplayName: Ellie
Body: <p>I found myself in this position as Black. I played Kb6, but the engine on chess.com suggested that the move Kb7  is a missed win, and the continuation below would have been winning for me. It gave no lines beyond what is below, and I can't see how this is a win for Black. Is this a fault with the engine, or is there some line that I've completely missed?</p>
  
  <pre><code>[Title "Unexplained"]
  [FEN "2b2r2/2p5/p1kb2qp/1p1p4/3P4/7P/PP1BQPP1/RNR3K1 b - - 0 1"]
  
  1...Kb7 2.Qe3 Rg8
  </code></pre>
  
  <p>In response to comments questioning if I have the position wrong or missed a root, I confirm I was a full rook down and felt this was a completely lost position. I have now included a screenshot demonstrating the strange opinion of the engine at chess.com</p>
  
  <p>I guess it's a bug with the engine then?</p>
  
  <p><a href="https://i.sstatic.net/2S6bU.png" rel="noreferrer"><img src="https://i.sstatic.net/2S6bU.png" alt="enter image description here"></a></p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-10-11T12:04:32.340Z
Comments.Text: Double check the position, and make sure that you did not leave out a black rook. If not, as Phonon said, you are just lost.
Comments.UserDisplayName: PhishMaster
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-10-11T12:55:23.427Z
Comments.Text: And this is why you should not rely on engines for game analysis
Comments.UserDisplayName: David
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-10-11T13:17:27.707Z
Comments.Text: @David I certainly wouldn't in the first instance, but after doing my own analysis on certain games I found interesting, it's usually worth using computer analysis to see if there were any big moves that were missed
Comments.UserDisplayName: Darren H
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-10-12T11:38:09.083Z
Comments.Text: Hi, this post seems to have received decent answers, if you have found one to be particularly satisfactory please consider [accepting](https://meta.stackexchange.com/questions/5234/how-does-accepting-an-answer-work) it, as it's important to give [closure](https://meta.stackexchange.com/questions/163740/actually-how-important-is-accepting-an-answer-to-the-stack-exchange-model/163743#163743) to well addressed posts. Thanks for considering it.
Comments.UserDisplayName: user929304
Tags: <analysis><positional-play>
Title: Why is this a missed win?
ThreadText: # Why is this a missed win?
  
  (Asked by: username_0 on 2019-10-11)
  
  I found myself in this position as Black. I played Kb6, but the engine on chess.com suggested that the move Kb7  is a missed win, and the continuation below would have been winning for me. It gave no lines beyond what is below, and I can't see how this is a win for Black. Is this a fault with the engine, or is there some line that I've completely missed?
  [Title "Unexplained"]
  [FEN "2b2r2/2p5/p1kb2qp/1p1p4/3P4/7P/PP1BQPP1/RNR3K1 b - - 0 1"]
  
  1...Kb7 2.Qe3 Rg8
  
  In response to comments questioning if I have the position wrong or missed a root, I confirm I was a full rook down and felt this was a completely lost position. I have now included a screenshot demonstrating the strange opinion of the engine at chess.com
  I guess it's a bug with the engine then?
  
  **Tags:** analysis, positional-play
  
  > **Comments:**
  > **username_1**: Double check the position, and make sure that you did not leave out a black rook. If not, as Phonon said, you are just lost.  
  > **username_2**: And this is why you should not rely on engines for game analysis  
  > **username_0**: @username_2 I certainly wouldn't in the first instance, but after doing my own analysis on certain games I found interesting, it's usually worth using computer analysis to see if there were any big moves that were missed  
  > **username_3**: Hi, this post seems to have received decent answers, if you have found one to be particularly satisfactory please consider [accepting](https://meta.stackexchange.com/questions/5234/how-does-accepting-an-answer-work) it, as it's important to give [closure](https://meta.stackexchange.com/questions/163740/actually-how-important-is-accepting-an-answer-to-the-stack-exchange-model/163743#163743) to well addressed posts. Thanks for considering it.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_4 on 2019-10-11. Score: 8 | Accepted answer
  
  This is **not** a missed win for black, both `Kb6` and `Kb7` are equally **losing for black** as you are simply a full rook down without any real compensation. `Qe3` move simply stops black's only way to breakthrough as it stops `Bxh3.` That is not white's only move either, `Kh1` and `Rc3` (though walks in the way of the knight) are sufficiently good for white too.
  
  So either:
  
  * The cloud engine didn't get to run sufficiently long and gave a wrong evaluation, or
  * you simply mis-read or mis-interpreted the evaluation of the engine, or
  * you're showing us the wrong position here.
  
  > **Comments:**
  > **username_0**: Thanks for your answer. I have updated my question which points to your first suggestion. I've since changed the settings from '10 seconds' to 'Unlimited' and increased lines to the maximum (5) from 3, and it still gives the same suggestion. Is there a way I can report this to chess.com as a bug then?  
  > **username_4**: @DarrenH Yeah both the textual and numerical evals are wrong, because probably the algorithm uses a very short ponder time for the engine to evaluate when parsing the whole game and in the `Kb7` line as you see its evaluation stems from a `depth 1` calculation, hence it's completely unreliable. You can report these things of course, try bottom left of your screen there's a help icon, once you click a "report bug" option should appear. For analysing your games with an engine, it's much simpler to just copy your game or its FEN to lichess (among others) and analyse there, all features are free.  
  > **username_2**: Black may have a slim chance for counterplay if White does not play precisely  
  > **username_0**: So the takeaway here then is to use Lichess rather than Chess.com. Do they use different software? Why is Lichess better?  
  > **username_0**: @username_2 yes that was what I was hoping for, unfortunately we were both playing pretty badly that day, but it seems my opponent wasn't playing badly enough!  
  > **username_4**: @DarrenH no! the takeaway here should be that both `Kb6` and `Kb7` are losing since that's what your question was. Now whether you wanna use lichess.org or chess.com is entirely up to you, I just gave you a practical recommendation.  
  > **username_2**: @DarrenH The takeaway is to not use software at all. You (hopefully) have grey matter on your brain. That's your chess engine!  
  
  ---
  
  ### Answer by username_1 on 2019-10-11. Score: 3
  
  Yes, it is a bug. I just plugged that updated position into Stockfish 10 running on a quad-core 2.9 GHz laptop, and it is still over +5.
  
  > **Comments:**
  > **username_1**: Still have not had time, but I will. We have had company coming this week for 10 days, and I am in the middle of a major email migration for a customer.  
  
  ---
  
  