Answers.Body: <p>The answer to your question is that <em><strong>there is no good reason to play this move.</strong></em> I plugged the position <em>before</em> Ke7 into StockFish on <a href="https://lichess.org" rel="nofollow noreferrer">lichess</a>. At depth 27, StockFish gives the position a <strong>+6.3</strong> for white. <em>After</em> Ke7, the analysis jumps to <strong>+10.8</strong> for white. Ke7 is a blunder.</p>
  
  <p>StockFish aside, the only thing that this move <em>does</em> do is remove the pin placed by the white Bishop on the f-pawn. A better move to accomplish this goal (and indeed the one that StockFish suggests in this position) is <strong>a6</strong>.</p>
  
  <p>This computer program is set to play generally poor moves - the 800 rating of the computer indicates that the computer is almost playing randomly - playing any better would increase its rating.</p>
  
  <p><em>Note: I analyzed the position with SF (and mentally) because I didn't just want to tell the OP that the computer was playing poorly [it is, but that wouldn't make a good stand-alone answer IMO].</em></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-01T14:03:58.573Z
Answers.Text: Could the downvoter please explain the downvote? Thanks!
Answers.UserDisplayName: Brandon_J
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-02T20:34:41.663Z
Answers.Text: I would also downvote. The move Ke7 is so clearly a blunder that to seek an opinion from Stockfish is like asking a supercomputer to add 1+1. The answer to why the move is played is that the computer, at this level, has been deliberately programmed to play badly, in order to give a chance to a weak human opponent.
Answers.UserDisplayName: Philip Roe
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-02T21:41:11.880Z
Answers.Text: @PhilipRoe edited. I know that the move was a blunder, I just didn't want to emphasize the obviousness of it to the OP.
Answers.UserDisplayName: Brandon_J
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-02T23:13:08.107Z
Answers.Text: @PhilipRoe i think this q/a has garnered some negative attention, which fails to recognize that I am just getting back into Chess and was seeking clarification. I thought it was a mistake. I wasnt sure how to confirm. I learned something. No reason that cant be useful
Answers.UserDisplayName: D. Ben Knoble
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-30T16:00:28.560Z
Answers.LastActivityDate: 2019-05-02T21:40:14.690Z
Answers.LastEditDate: 2019-05-02T21:40:14.690Z
Answers.UserDisplayName: Brandon_J
Body: <p>Not having played chess in ~5 years, I started playing against the computer on my phone at ELO~800 (I've since reached ~900). I do not know what engine the app uses (<code>Chess</code> for iPhone by <strong>Mastersoft Ltd</strong>).</p>
  
  <p>In my most recent game, which I ended up winning, the computer (Black) played what looked to me like an odd move (9. ...Ke7).</p>
  
  <p>I'm wondering if anyone can shed some insight into this particular move. Why play it?</p>
  
  <pre><code>[fen ""]
  
  1. d4 e6 2. h4 Be7 3. Bf4 Bxh4 4. e3 Qf6 5. Bc4 Nc6 6. Nf3 Na5 7. Bb5 Qd8 8. Nxh4 g6 9. Qd3 Ke7
  </code></pre>
  
  <hr>
  
  <p>For the curious, the full game is</p>
  
  <pre><code>[fen ""]
  
  1. d4 e6 2. h4 Be7 3. Bf4 Bxh4 4. e3 Qf6 5. Bc4 Nc6 6. Nf3 Na5 7. Bb5 Qd8 8. Nxh4 g6 9. Qd3 Ke7 10. Qa3+ c5 11. Qxc5+ Ke8 12. Bd3 Qb6 13. Qe5 f6 14. Qe4 Qxb2 15. O-O Kf8 16. Nd2 Ke7 17. d5 d6 18. Qa4 e5 19. Qxa5 Kf7 20. Qc7+ Kf8 21. Nc4 Qb4 22. Rad1 exf4 23. exf4 Bg4 24. Rde1 Qb5 25. Qxd6+ Kg7 26. Na3 Qd7 27. Qc5 Rd8 28. Nc4 a6 29. f3 Qc8 30. Qa5 Bd7 31. Nd6 Qb8 32. Nf7 h6 33. Nxh8 Kxh8 34. Nxg6+ Kh7 35. Re7+ Nxe7 36. Nxe7+ Kh8 37. Qc3 Qd6 38. Nf5 Qf8 39. d6 Bxf5 40. Bxf5 Rxd6 41. Qb3 Kg7 42. Qxb7+ Kh8 43. Qh7#
  </code></pre>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-30T14:34:32.773Z
Comments.Text: Not sure if I got those tags right (always the hardest part in asking questions on sites I'm unfamiliar with).
Comments.UserDisplayName: D. Ben Knoble
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-30T15:05:39.603Z
Comments.Text: Why ponder `9...Ke7` as opposed to all the other moves the computer played? :) Clearly, this is a very weak computer program (or at least set to play at such a level), therefore the depth of calculation is very small and the evaluation very rough, which means sometimes it will make random moves, such as useless king moves or hang pieces (like in your game). So there's no reason for playing a move like `Ke7` in that position, it's a blunder pure and simple. Don't bother understanding the play of weak programs. Instead, either consider playing a stronger one, or play online against humans.
Comments.UserDisplayName: Ellie
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-30T15:10:51.947Z
Comments.Text: @Phonon fair point; the computer gets stronger as i play it, so hopefully in the future the silliness stops.
Comments.UserDisplayName: D. Ben Knoble
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-02T23:00:28.313Z
Comments.Text: Your opponent is simpley bad
Comments.UserDisplayName: David
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-02T23:11:23.337Z
Comments.Text: @David yes, thats what the answer says about the computer...
Comments.UserDisplayName: D. Ben Knoble
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-02T23:52:49.427Z
Comments.Text: @D.BenKnoble Just wanted to make a quick summary
Comments.UserDisplayName: David
Tags: <engines><analysis><middlegame>
Title: Why did the (Black) computer play 9. ... Ke7 here?
ThreadText: # Why did the (Black) computer play 9. ... Ke7 here?
  
  (Asked by: username_0 on 2019-04-30)
  
  Not having played chess in ~5 years, I started playing against the computer on my phone at ELO~800 (I've since reached ~900). I do not know what engine the app uses (Chess for iPhone by Mastersoft Ltd).
  In my most recent game, which I ended up winning, the computer (Black) played what looked to me like an odd move (9. ...Ke7).
  I'm wondering if anyone can shed some insight into this particular move. Why play it?
  [fen ""]
  
  1. d4 e6 2. h4 Be7 3. Bf4 Bxh4 4. e3 Qf6 5. Bc4 Nc6 6. Nf3 Na5 7. Bb5 Qd8 8. Nxh4 g6 9. Qd3 Ke7
  
  
  For the curious, the full game is
  [fen ""]
  
  1. d4 e6 2. h4 Be7 3. Bf4 Bxh4 4. e3 Qf6 5. Bc4 Nc6 6. Nf3 Na5 7. Bb5 Qd8 8. Nxh4 g6 9. Qd3 Ke7 10. Qa3+ c5 11. Qxc5+ Ke8 12. Bd3 Qb6 13. Qe5 f6 14. Qe4 Qxb2 15. O-O Kf8 16. Nd2 Ke7 17. d5 d6 18. Qa4 e5 19. Qxa5 Kf7 20. Qc7+ Kf8 21. Nc4 Qb4 22. Rad1 exf4 23. exf4 Bg4 24. Rde1 Qb5 25. Qxd6+ Kg7 26. Na3 Qd7 27. Qc5 Rd8 28. Nc4 a6 29. f3 Qc8 30. Qa5 Bd7 31. Nd6 Qb8 32. Nf7 h6 33. Nxh8 Kxh8 34. Nxg6+ Kh7 35. Re7+ Nxe7 36. Nxe7+ Kh8 37. Qc3 Qd6 38. Nf5 Qf8 39. d6 Bxf5 40. Bxf5 Rxd6 41. Qb3 Kg7 42. Qxb7+ Kh8 43. Qh7#
  
  **Tags:** engines, analysis, middlegame
  
  > **Comments:**
  > **username_0**: Not sure if I got those tags right (always the hardest part in asking questions on sites I'm unfamiliar with).  
  > **username_1**: Why ponder `9...Ke7` as opposed to all the other moves the computer played? :) Clearly, this is a very weak computer program (or at least set to play at such a level), therefore the depth of calculation is very small and the evaluation very rough, which means sometimes it will make random moves, such as useless king moves or hang pieces (like in your game). So there's no reason for playing a move like `Ke7` in that position, it's a blunder pure and simple. Don't bother understanding the play of weak programs. Instead, either consider playing a stronger one, or play online against humans.  
  > **username_0**: @Phonon fair point; the computer gets stronger as i play it, so hopefully in the future the silliness stops.  
  > **username_2**: Your opponent is simpley bad  
  > **username_0**: @username_2 yes, thats what the answer says about the computer...  
  > **username_2**: @D.BenKnoble Just wanted to make a quick summary  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_3 on 2019-04-30. Score: 2 | Accepted answer
  
  The answer to your question is that ***there is no good reason to play this move.*** I plugged the position *before* Ke7 into StockFish on [lichess](https://lichess.org). At depth 27, StockFish gives the position a **+6.3** for white. *After* Ke7, the analysis jumps to **+10.8** for white. Ke7 is a blunder.
  
  StockFish aside, the only thing that this move *does* do is remove the pin placed by the white Bishop on the f-pawn. A better move to accomplish this goal (and indeed the one that StockFish suggests in this position) is **a6**.
  
  This computer program is set to play generally poor moves - the 800 rating of the computer indicates that the computer is almost playing randomly - playing any better would increase its rating.
  
  *Note: I analyzed the position with SF (and mentally) because I didn't just want to tell the OP that the computer was playing poorly [it is, but that wouldn't make a good stand-alone answer IMO].*
  
  > **Comments:**
  > **username_3**: Could the downvoter please explain the downvote? Thanks!  
  > **username_4**: I would also downvote. The move Ke7 is so clearly a blunder that to seek an opinion from Stockfish is like asking a supercomputer to add 1+1. The answer to why the move is played is that the computer, at this level, has been deliberately programmed to play badly, in order to give a chance to a weak human opponent.  
  > **username_3**: @PhilipRoe edited. I know that the move was a blunder, I just didn't want to emphasize the obviousness of it to the OP.  
  > **username_0**: @PhilipRoe i think this q/a has garnered some negative attention, which fails to recognize that I am just getting back into Chess and was seeking clarification. I thought it was a mistake. I wasnt sure how to confirm. I learned something. No reason that cant be useful  
  
  ---
  
  