Answers.Body: <p>You might want to go with <a href="http://www.kenilworthchessclub.org/games/java/2009/hamppe-meitner.htm" rel="nofollow noreferrer">http://www.kenilworthchessclub.org/games/java/2009/hamppe-meitner.htm</a> however no guarantees on its being up to date.</p>
  
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Answers.Text: by the way, 8. d4 and 9. d4 might be the bone crushers you mentioned.
Answers.UserDisplayName: starrin
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Answers.CreationDate: 2022-02-05T06:32:33.690Z
Answers.Text: This appears not up to date, running it through Leela it immediately finds improvements for both sides. :D For instance it is stated that after Kc3 d4+ is a mistake which does not appear to be the case, rather after d4+ Kb3 Qxe4 Black seems to have more than sufficient compensation for the piece.
Answers.UserDisplayName: koedem
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Answers.CreationDate: 2022-02-05T16:36:30.490Z
Answers.Text: This would be indeed a great resource, style-wise, with extensive analysis and alternatives...were it not for the fact that the analysis is outdated :-) Too bad. But for training, it probably will do, since none of my chess kids runs on Leela and they have to believe me :-)
Answers.UserDisplayName: Hauke Reddmann
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Answers.UserDisplayName: starrin
Answers.Body: <p>Using Stockfish 14 at depth up to 25 I find:</p>
  <pre><code>4 Kxf2 (Ke2? Bxg1! 5 Rxg1 d5 {-6.3}) Qh4+
  5 Ke3 (g3 Qxe4! 6 Qe1/Qe2 Qxh1 7 Qxe5+ Kf8
    (Ne7? 8 Nf3! {+1.3}) 8 Bg2/Qxc7 {-0.2}) Qf4+
  6 Kd3 d5
  7 Qe1 (Kc3 d4+ 8 Kb3 Qxe4 {-0.9} (Be6+? 9 c4! {+0.4})) Nf6
  8 g3 dxe4+ (Qg4 9 c3 {+0.1})
  9 Kc3 Nd5+ 10 Kb3 Qf6 11 c4 b5 (Nc6)
  12 cxb5 (cxd5? bxa4+! {-0.9}) Nd7 {-0.7}
  </code></pre>
  <pre><code>[fen &quot;rnbqk1nr/pppp1ppp/8/4p3/N3P3/8/PPPP1bPP/R1BQKBNR w - - 0 4&quot;]
  
  4. Kxf2 (4. Ke2? Bxg1! 5. Rxg1 d5 {-6.3}) Qh4+ 5. Ke3 (5. g3 Qxe4! 6. Qe1 (6. Qe2 Qxh1) Qxh1 7. Qxe5+ Kf8 (7...Ne7? 8. Nf3! {+1.3}) 8. Bg2 (8. Qxc7) {-0.2}) Qf4+ 6. Kd3 d5 7. Qe1 (7. Kc3 d4+ 8. Kb3 Qxe4 {-0.9} (8...Be6+? 9. c4! {+0.4})) Nf6 8. g3 dxe4+ (8...Qg4 9. c3 {+0.1}) 9. Kc3 Nd5+ 10. Kb3 Qf6 11. c4 b5 (11...Nc6) 12. cxb5 (12. cxd5? bxa4+! {-0.9}) Nd7 {-0.7}
  </code></pre>
  <p>Figures are evaluations in terms of advantage to White in pawns. These are rough --- different evaluations might give slightly different figures.</p>
  <p>If there is a line by which White can guarantee a winning position, Stockfish can't find it at that depth. I get the impression that Stockfish reckons that Black has a slight advantage.</p>
  <p><a href="https://www.365chess.com/opening.php?m=5&amp;n=448&amp;ms=e4.e5.Nc3.Bc5&amp;ns=3.5.55.448" rel="nofollow noreferrer">365chess.com</a>'s openings-database rates 3 Na4 Bxf2+ at -1.00, and says that it is very rare: only 28 3 Na4 games of which 24 are 3 Na4 Bxf2+, compared to 551 for 3 Bc4. Game totals are of games in its big database.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-02-05T06:35:28.377Z
Answers.Text: Thanks. I've corrected the move numbering (our replayer understands full FEN with the move number specified), and restored a copy of the notation in *plain text*. The replayer has some nice features but looks wretched for those of us who are visually impaired and need to use dark mode (all squares are dark and black pawns are invisible) and/or low resolution (either the moves aren't shown or they are shown below the board, so the navigation controls and board can't be shown on screen at the same time).
Answers.UserDisplayName: Rosie F
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Answers.LastEditDate: 2022-02-05T06:31:15.667Z
Answers.UserDisplayName: Rosie F
Answers.Body: <p>I'm not completely sure about your question, but if you're trying to find a win for one side in the game, there were 5 critical positions, 2 for black and 3 for white, in which they could have won the game.</p>
  <p>Black initially had a critical position after 7.Kc3 and could have responded with the winning d4+.</p>
  <p>Black plays 7...Qxe5 instead, giving white a winning position after white plays 8.d4.</p>
  <p>White blunders back, playing 8.Kb3, allowing black to win after he plays 8...d4.</p>
  <p>White is also winning after Black played 8...Na6 after 9.d4.</p>
  <p>Lastly, after Black played 11...Nc5+, White can win with 12.Kb5.</p>
  <p>Four of the five critical positions in this game revolve pushing the pawn to the d4 square.</p>
  
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Answers.UserDisplayName: Yash Jain
Body: <pre><code>[FEN &quot;&quot;]
  
  1.e4 e5 2.Nc3 Bc5 3.Na4 Bxf2+
  </code></pre>
  <p>For those of you who never heard of Hamppe-Meitner. Now I dimly remember that a super engine somewhere found a White win, but even the bringer of the news ceded that a super-duper engine could reverse that. (See e.g. <a href="https://www.chessgames.com/perl/chessgame?gid=1250160" rel="nofollow noreferrer">here</a> for the complete game and how they still discuss...)</p>
  <p>Can you link me to a human-annotated (a mere list with cryptical &quot;+0.5 after Kj9&quot; is quite useless, see below) computer analysis, also <em>with</em> evaluations of the side variants? Mustn't be each and any move, but at least the sensible ones, if one can talk of sensible in that crazy positions...)</p>
  <p>The greater plan is to turn it into a Euwe-style &quot;I test myself&quot; test for the chess kids I train, to boost their imagination. Of course I must deliver when I get asked why Kj9 botches the draw!</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-02-04T10:26:28.517Z
Comments.Text: I don't understand the question.
Comments.UserDisplayName: SmallChess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-02-04T13:27:30.293Z
Comments.Text: https://www.youtube.com/watch?v=LZ9iia2aIQc at about 6:30 might be what you are talking about, where it says an engine has white with an advantage of about a pawn in a side line, but it doesn't go into depth, and it's not entirely clear to me what you want anyway.
Comments.UserDisplayName: Ian Bush
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-02-04T13:33:20.233Z
Comments.Text: What is **Kj9**?  My chessboard only has files from a to h.
Comments.UserDisplayName: SecretAgentMan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-02-05T16:25:12.460Z
Comments.Text: @SecretAgentMan: Kj9 is a joke. Read "any move".
Comments.UserDisplayName: Hauke Reddmann
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-02-22T18:49:53.217Z
Comments.Text: @HaukeReddmann forgive me. I am an idiot.
Comments.UserDisplayName: SecretAgentMan
Tags: <engines><analysis><draw><annotation><reference-request>
Title: Hamppe-Meitner, the final verdict?
ThreadText: # Hamppe-Meitner, the final verdict?
  
  (Asked by: username_0 on 2022-02-04)
  
  ```
  [FEN ""]
  
  1.e4 e5 2.Nc3 Bc5 3.Na4 Bxf2+
  
  ```
  
  For those of you who never heard of Hamppe-Meitner. Now I dimly remember that a super engine somewhere found a White win, but even the bringer of the news ceded that a super-duper engine could reverse that. (See e.g. [here](https://www.chessgames.com/perl/chessgame?gid=1250160) for the complete game and how they still discuss...)
  
  Can you link me to a human-annotated (a mere list with cryptical "+0.5 after Kj9" is quite useless, see below) computer analysis, also *with* evaluations of the side variants? Mustn't be each and any move, but at least the sensible ones, if one can talk of sensible in that crazy positions...)
  
  The greater plan is to turn it into a Euwe-style "I test myself" test for the chess kids I train, to boost their imagination. Of course I must deliver when I get asked why Kj9 botches the draw!
  
  **Tags:** engines, analysis, draw, annotation, reference-request
  
  > **Comments:**
  > **username_1**: I don't understand the question.  
  > **username_2**: https://www.youtube.com/watch?v=LZ9iia2aIQc at about 6:30 might be what you are talking about, where it says an engine has white with an advantage of about a pawn in a side line, but it doesn't go into depth, and it's not entirely clear to me what you want anyway.  
  > **username_3**: What is **Kj9**?  My chessboard only has files from a to h.  
  > **username_0**: @username_3: Kj9 is a joke. Read "any move".  
  > **username_3**: @username_0 forgive me. I am an idiot.  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_4 on 2022-02-04. Score: 3
  
  You might want to go with <http://www.kenilworthchessclub.org/games/java/2009/hamppe-meitner.htm> however no guarantees on its being up to date.
  
  > **Comments:**
  > **username_4**: by the way, 8. d4 and 9. d4 might be the bone crushers you mentioned.  
  > **username_5**: This appears not up to date, running it through Leela it immediately finds improvements for both sides. :D For instance it is stated that after Kc3 d4+ is a mistake which does not appear to be the case, rather after d4+ Kb3 Qxe4 Black seems to have more than sufficient compensation for the piece.  
  > **username_0**: This would be indeed a great resource, style-wise, with extensive analysis and alternatives...were it not for the fact that the analysis is outdated :-) Too bad. But for training, it probably will do, since none of my chess kids runs on Leela and they have to believe me :-)  
  
  ---
  
  ### Answer by username_6 on 2022-02-04. Score: 3
  
  Using Stockfish 14 at depth up to 25 I find:
  
  ```
  4 Kxf2 (Ke2? Bxg1! 5 Rxg1 d5 {-6.3}) Qh4+
  5 Ke3 (g3 Qxe4! 6 Qe1/Qe2 Qxh1 7 Qxe5+ Kf8
    (Ne7? 8 Nf3! {+1.3}) 8 Bg2/Qxc7 {-0.2}) Qf4+
  6 Kd3 d5
  7 Qe1 (Kc3 d4+ 8 Kb3 Qxe4 {-0.9} (Be6+? 9 c4! {+0.4})) Nf6
  8 g3 dxe4+ (Qg4 9 c3 {+0.1})
  9 Kc3 Nd5+ 10 Kb3 Qf6 11 c4 b5 (Nc6)
  12 cxb5 (cxd5? bxa4+! {-0.9}) Nd7 {-0.7}
  
  ```
  
  ```
  [fen "rnbqk1nr/pppp1ppp/8/4p3/N3P3/8/PPPP1bPP/R1BQKBNR w - - 0 4"]
  
  4. Kxf2 (4. Ke2? Bxg1! 5. Rxg1 d5 {-6.3}) Qh4+ 5. Ke3 (5. g3 Qxe4! 6. Qe1 (6. Qe2 Qxh1) Qxh1 7. Qxe5+ Kf8 (7...Ne7? 8. Nf3! {+1.3}) 8. Bg2 (8. Qxc7) {-0.2}) Qf4+ 6. Kd3 d5 7. Qe1 (7. Kc3 d4+ 8. Kb3 Qxe4 {-0.9} (8...Be6+? 9. c4! {+0.4})) Nf6 8. g3 dxe4+ (8...Qg4 9. c3 {+0.1}) 9. Kc3 Nd5+ 10. Kb3 Qf6 11. c4 b5 (11...Nc6) 12. cxb5 (12. cxd5? bxa4+! {-0.9}) Nd7 {-0.7}
  
  ```
  
  Figures are evaluations in terms of advantage to White in pawns. These are rough --- different evaluations might give slightly different figures.
  
  If there is a line by which White can guarantee a winning position, Stockfish can't find it at that depth. I get the impression that Stockfish reckons that Black has a slight advantage.
  
  [365chess.com](https://www.365chess.com/opening.php?m=5&n=448&ms=e4.e5.Nc3.Bc5&ns=3.5.55.448)'s openings-database rates 3 Na4 Bxf2+ at -1.00, and says that it is very rare: only 28 3 Na4 games of which 24 are 3 Na4 Bxf2+, compared to 551 for 3 Bc4. Game totals are of games in its big database.
  
  > **Comments:**
  > **username_6**: Thanks. I've corrected the move numbering (our replayer understands full FEN with the move number specified), and restored a copy of the notation in *plain text*. The replayer has some nice features but looks wretched for those of us who are visually impaired and need to use dark mode (all squares are dark and black pawns are invisible) and/or low resolution (either the moves aren't shown or they are shown below the board, so the navigation controls and board can't be shown on screen at the same time).  
  
  ---
  
  ### Answer by username_7 on 2022-02-05. Score: 0
  
  I'm not completely sure about your question, but if you're trying to find a win for one side in the game, there were 5 critical positions, 2 for black and 3 for white, in which they could have won the game.
  
  Black initially had a critical position after 7.Kc3 and could have responded with the winning d4+.
  
  Black plays 7...Qxe5 instead, giving white a winning position after white plays 8.d4.
  
  White blunders back, playing 8.Kb3, allowing black to win after he plays 8...d4.
  
  White is also winning after Black played 8...Na6 after 9.d4.
  
  Lastly, after Black played 11...Nc5+, White can win with 12.Kb5.
  
  Four of the five critical positions in this game revolve pushing the pawn to the d4 square.
  
  
  ---
  
  