Answers.Body: <p>From my analysis, the line you give appears to be the best way White can play. After 9.Qd2, Stockfish 10 at depth 28 gives roughly +1. So I think it qualifies as a refutation of 3...h5.</p>
  
  <p>I couldn't find any games where 6.Ng5 was played, but I did find a game that reached the same position on move 6 via transposition. The game was from 1788 (!) in the "London Casual Games" between two players named Cotter and Von Bruehl:</p>
  
  <pre><code>[White "Cotter"]
  [Black "Von Bruehl"]
  [Event "London Casual Games"]
  [Date "1788"]
  
  [fen ""]
  
  1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h5 6.d4 {Transposing to the diagram you gave} f6 7.Bxf4 fxg5 8.hxg5 (8.Bxg5 {Is stronger, following your line}) d5 9.e5 Bf5 10.Bd3 Ne7 11.O-O Bg7 12.Bg3 Rf8 13.Bh4 Qd7 14.Nc3 a6 15.Qe2 Nbc6 16.Bf2 O-O-O 17.Na4 Bxd3 18.Qxd3 Nxe5 19.Qb3 b5 20.dxe5 bxa4 21.Qc3 d4 22.Qd3 Qb5 23.Qa3 Ng6 24.b3 Bxe5 25.bxa4 Qc6 26.Rab1 0-1.
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-03T07:39:03.120Z
Answers.Text: Thank you very much for this excellent answer! For a moment there I thought of calling it the Cotter Gambit, but not after Cotter's weak follow-up.
Answers.UserDisplayName: bof
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-03T09:15:01.453Z
Answers.Text: Is White's advantage smaller (according to the engine) if he simply plays the positionnal 4.h4 after 1.e4 e5 2.f4 ef4 3.Nf3 h5?
Answers.UserDisplayName: Evargalo
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-03T12:51:40.880Z
Answers.Text: After you gave me the idea of looking for transpositions from the Allgaier Gambit, I found another one. (There shouldn't be very many, because after 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h5 the normal move is 6.Bc4! not 6.d4.)
Answers.UserDisplayName: bof
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-03T12:51:55.417Z
Answers.Text: I found this in Colin Leach's booklet *KGA: Allgaier and Kieseritzky Gambits*. J. Weiss–von Gompers, Vienna 1906. 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h5 6.d4 f6 7.Bxf4 fxg5 8.hxg5 d6 9.Nc3 Bg7 10.Qd2 Ne7 11.O-O-O Ng6 12.g3 Nc6 13.Bb5 Bd7 14.Bxc6 Bxc6 15.Rhe1 Qe7 16.Nd5 Qf7 17.c4 O-O-O 18.rf1 Qd7 19,Qa5 Kb8 20. c5 Bxd5 21.exd5 h4 22.Rd3 Qf5 23.Qxc7+ Kxc7 24.Bxd6+ Rxd6 25.cxd6+ Kxd6 26.Rxf6 h3 27.Rxf5 h3 28.Rf1 h2 29.Rh1 Bxd4 30.Rd3 Bf2 31.Kd1 Rh3 0-1
Answers.UserDisplayName: bof
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-03T18:31:50.073Z
Answers.Text: @bof interesting, so from what we've found it appears no one has ever played the stronger 8.Bxg5.
Answers.UserDisplayName: Inertial Ignorance
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-03T18:33:58.010Z
Answers.Text: @Evargalo Actually after 4.h4 Stockfish says Black is at least equal since he has time to strike in the centre with 4...d5.
Answers.UserDisplayName: Inertial Ignorance
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-04T08:51:31.830Z
Answers.Text: Please beware of using Stockfish evaluations for opening soundness! They are often quite volatile and dependent on how much time you run the engine itself!
Answers.UserDisplayName: David
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-04T09:34:07.473Z
Answers.Text: @David I'm well aware of the limitations of Stockfish. For Stockfish 10 I've chosen a setting where the evaluations don't change dramatically depending on who's move it is. In addition, depth 28 is sufficient to get a general idea of a line's soundness, especially in the tactical position after 8.Bxg5. If I was building a serious repertoire I might let it think to depth 35-40.
Answers.UserDisplayName: Inertial Ignorance
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-04T09:37:29.587Z
Answers.Text: @InertialIgnorance if you were building a serious repertoire you wouldn't be analyzing this line in the first place!
Answers.UserDisplayName: David
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-04T10:30:46.437Z
Answers.Text: @David Not necessarily I might want to play the King's Gambit and need to know a proper refutation for 3...h5 :)
Answers.UserDisplayName: Inertial Ignorance
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-09-03T06:46:53.520Z
Answers.LastActivityDate: 2019-09-03T18:27:27.423Z
Answers.LastEditDate: 2019-09-03T18:27:27.423Z
Answers.UserDisplayName: Inertial Ignorance
Body: <p>Has this gambit (6.Ng5!) been played? (I only found games with 6.Ne5.) Is it any good? Is it the refutation of Black's silly 3...h5 (the <a href="https://en.wikipedia.org/wiki/King%27s_Gambit#Wagenbach_Defense:_3...h5" rel="nofollow noreferrer">Wagenbach Defense</a>)?</p>
  
  <pre><code>[FEN ""]
  
  1.e4 e5 2.f4 exf4 3.Nf3 h5 4.d4 g5 5.h4 g4 6.Ng5 f6 7.Bxf4 fxg5 8.Bxg5 Be7 9.Qd2
  </code></pre>
  
Tags: <opening><gambits><kings-gambit>
Title: King's Gambit, Wagenbach Defense 1.e4 e5 2.f4 exf4 3.Nf3 h5
ThreadText: # King's Gambit, Wagenbach Defense 1.e4 e5 2.f4 exf4 3.Nf3 h5
  
  (Asked by: username_0 on 2019-09-03)
  
  Has this gambit (6.Ng5!) been played? (I only found games with 6.Ne5.) Is it any good? Is it the refutation of Black's silly 3...h5 (the Wagenbach Defense)?
  [FEN ""]
  
  1.e4 e5 2.f4 exf4 3.Nf3 h5 4.d4 g5 5.h4 g4 6.Ng5 f6 7.Bxf4 fxg5 8.Bxg5 Be7 9.Qd2
  
  **Tags:** opening, gambits, kings-gambit
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2019-09-03. Score: 6 | Accepted answer
  
  From my analysis, the line you give appears to be the best way White can play. After 9.Qd2, Stockfish 10 at depth 28 gives roughly +1. So I think it qualifies as a refutation of 3...h5.
  I couldn't find any games where 6.Ng5 was played, but I did find a game that reached the same position on move 6 via transposition. The game was from 1788 (!) in the "London Casual Games" between two players named Cotter and Von Bruehl:
  [White "Cotter"]
  [Black "Von Bruehl"]
  [Event "London Casual Games"]
  [Date "1788"]
  
  [fen ""]
  
  1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h5 6.d4 {Transposing to the diagram you gave} f6 7.Bxf4 fxg5 8.hxg5 (8.Bxg5 {Is stronger, following your line}) d5 9.e5 Bf5 10.Bd3 Ne7 11.O-O Bg7 12.Bg3 Rf8 13.Bh4 Qd7 14.Nc3 a6 15.Qe2 Nbc6 16.Bf2 O-O-O 17.Na4 Bxd3 18.Qxd3 Nxe5 19.Qb3 b5 20.dxe5 bxa4 21.Qc3 d4 22.Qd3 Qb5 23.Qa3 Ng6 24.b3 Bxe5 25.bxa4 Qc6 26.Rab1 0-1.
  
  > **Comments:**
  > **username_0**: Thank you very much for this excellent answer! For a moment there I thought of calling it the Cotter Gambit, but not after Cotter's weak follow-up.  
  > **username_2**: Is White's advantage smaller (according to the engine) if he simply plays the positionnal 4.h4 after 1.e4 e5 2.f4 ef4 3.Nf3 h5?  
  > **username_0**: After you gave me the idea of looking for transpositions from the Allgaier Gambit, I found another one. (There shouldn't be very many, because after 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h5 the normal move is 6.Bc4! not 6.d4.)  
  > **username_0**: I found this in Colin Leach's booklet *KGA: Allgaier and Kieseritzky Gambits*. J. Weiss–von Gompers, Vienna 1906. 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5 h5 6.d4 f6 7.Bxf4 fxg5 8.hxg5 d6 9.Nc3 Bg7 10.Qd2 Ne7 11.O-O-O Ng6 12.g3 Nc6 13.Bb5 Bd7 14.Bxc6 Bxc6 15.Rhe1 Qe7 16.Nd5 Qf7 17.c4 O-O-O 18.rf1 Qd7 19,Qa5 Kb8 20. c5 Bxd5 21.exd5 h4 22.Rd3 Qf5 23.Qxc7+ Kxc7 24.Bxd6+ Rxd6 25.cxd6+ Kxd6 26.Rxf6 h3 27.Rxf5 h3 28.Rf1 h2 29.Rh1 Bxd4 30.Rd3 Bf2 31.Kd1 Rh3 0-1  
  > **username_1**: @username_0 interesting, so from what we've found it appears no one has ever played the stronger 8.Bxg5.  
  > **username_1**: @username_2 Actually after 4.h4 Stockfish says Black is at least equal since he has time to strike in the centre with 4...d5.  
  > **username_3**: Please beware of using Stockfish evaluations for opening soundness! They are often quite volatile and dependent on how much time you run the engine itself!  
  > **username_1**: @username_3 I'm well aware of the limitations of Stockfish. For Stockfish 10 I've chosen a setting where the evaluations don't change dramatically depending on who's move it is. In addition, depth 28 is sufficient to get a general idea of a line's soundness, especially in the tactical position after 8.Bxg5. If I was building a serious repertoire I might let it think to depth 35-40.  
  > **username_3**: @InertialIgnorance if you were building a serious repertoire you wouldn't be analyzing this line in the first place!  
  > **username_1**: @username_3 Not necessarily I might want to play the King's Gambit and need to know a proper refutation for 3...h5 :)  
  
  ---
  
  