Answers.Body: <p>I found the following game, which reaches the position at move 19 by transposition. It also indicates that the sacrifice is sound, with the continuation 20. Qe3</p>
  <pre><code>[Event &quot;It&quot;]
  [Site &quot;St. Lo (France)&quot;]
  [Date &quot;2012.07.10&quot;]
  [Round &quot;5&quot;]
  [White &quot;Devallee, Jeremie (FRA)&quot;]
  [Black &quot;Duchateau, Thomas (FRA)&quot;]
  [Result &quot;1-0&quot;]
  [Eco &quot;B21&quot;]
  [Annotator &quot;&quot;]
  [Source &quot;&quot;]
  [Startply &quot;39&quot;]
  [FEN &quot;&quot;]
  
  1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Nf3 a6 6.Bc4 Ne7 7.Bg5 f6 8.Be3 Ng6 9.O-O b5 10.Bb3 Nc6 11.Nd5 exd5 12.exd5 Nce5 13.Nxe5 fxe5 14.d6 Bb7 15.f4 exf4 16.Re1 fxe3 17.Rxe3+ Be7 18.Qd4 Qc8 19.Rxe7+ Nxe7 20.Qe3 Qd8 21.Re1 Rc8 22.Qd4 Qa5 23.Rxe7+ Kd8 24.Re8+ 1-0
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-31T12:57:07.740Z
Answers.Text: Nice find! Devallee's 20.Qe3!? (instead of my 20.Qe5) prevents Black's check on b6, but SF can't find any winning line for White here because the Queen's placement on e3 (no access to g7 or h5) isn't as threatening as on e5. Duchateau's 21...Rc8?! looks like a minor mistake, and 22...Qa5?? is a huge blunder.
Answers.UserDisplayName: HTTP 410
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-23T20:45:02.763Z
Answers.Text: According to SF, the best line for Black is 20...Qd8 21.Re1 a5! and that leads to an approximately equal position. White has enough compensation for the sacrifices, but no more.
Answers.UserDisplayName: HTTP 410
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-31T07:57:41.247Z
Answers.LastActivityDate: 2021-12-31T07:57:41.247Z
Answers.UserDisplayName: Herb
Body: <p>Working my way through Hannes Langrock's book on the modern Morra Gambit (second edition), I came across an interesting sacrifice that he believes is at best worth a draw. Indeed that's also Stockfish's initial conclusion. But when I analyse it for a while (with SF 14.1 on 32 cores), it actually appears to be very strong, maybe even winning. The line starts with 11 Nd5, the critical point is 19 Rxe7, and my novelties are 20 Qe5 and 21 Kh1.</p>
  <p>Have I missed something in my notes to the attached analysis, or is this double-piece sac really sound?</p>
  <p><em>[In case it matters, I hover around Glicko 2200 on Lichess]</em></p>
  <pre><code>[Event &quot;Engine Analysis of Zakharov-Gusev (Tula 2001)&quot;]
  [White &quot;SF 14.1&quot;]
  [Black &quot;SF 14.1&quot;]
  [Result &quot;1-0&quot;]
  [ECO &quot;B21&quot;]
  [Annotator &quot;Mark Pearce&quot;]
  [PlyCount &quot;67&quot;]
  [FEN &quot;RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1&quot;]
  
  1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Nf3 Nc6 6.Bc4 a6 7.O-O Nge7 8.Bg5! f6 9.Be3 b5     10.Bb3 Ng6 11.Nd5!? {Zacharov's daring innovation.} exd5 12.exd5 Nce5 (12...Na5? 13.Re1! Be7 14.d6 {Black is in big trouble}) 13.d6! Bb7 14.Nxe5 fxe5 (14...Nxe5? 15.Re1 Qb8 16.Bc5 {Black's position is hopeless}) 15.f4! exf4! (15...Qf6? 16.fxe5 Qxe5 17.Bf7+ Kd8 18.Bb6+ Kc8 19.Re1 {Winning}) 16.Re1! {Zakharov had to foresee this position before he played his sacrifice on move 11!} 16...fxe3 17.Rxe3+ Be7 18.Qd4 Qc8! (18... Qb8? 19.dxe7 Qa7 20.Bf7+! Kxf7 21.e8=Q+ Rhxe8 22.Rf1+ Kg8 23.Qxa7 Rxe3 24.Qxe3 {1-0 Zahkarov-Gusev, Tula 2001}) (18...Rf8? 19.dxe7 Nxe7 20.Rae1 Rf6 21.Qc5! d6 22.Rxe7+ Qxe7 23.Rxe7+ Kxe7 24.Qc7+ {Winning}) 19.Rxe7+! {Already two pieces down, White makes a further sacrifice!} (19.Rae1!? Qc6= {After this more prosaic line Hannes Langrock (in his &quot;Modern Morra Gambit, Second Edition&quot;) believes the position looks like a draw, and the 11 games following this line in Chessbase's Mega 2020 database agree - there are 8 draws and only 3 wins for White.}) 19...Nxe7 20.Qe5! (20.Re1? Qc6! 21.Bd5! O-O-O! (21...Qxd5 22.Rxe7+ Kd8 23.Qb6+ Kc8 24. Qc7#) (21...Qxd6 22.Bf7+ Kxf7 23.Qxd6 Rhe8 24.Qxd7!) 22.Bxc6 Nxc6! {This is the only line analysed by Langrock - and White is losing})(20.Qe3? Qd8 21.Re1 a5!=)  20...Qd8 21.Kh1! {A beautifully quiet move that prevents ...Qb6+ and a potential escape with ...0-0-0. This is a crazy position - White has sacrified two pieces for a stranglehold on e7, but surprisingly doesn't need to hurry with exploitation.} 21...Rf8 22.Qh5+! g6 23.Qe5 {White quietly takes time to open the c3-h8 diagonal before doubling on the e-file. This is possible because Black is almost paralysed.} 23...Rf2 (23...Rf5 24.Qg7 Ra7! (24...Be4 25.Re1 Rc8 26.h3 Rc1 27.Rxc1 Bxg2+ 28.Kh2! Bd5 29.Bxd5 Rxd5 30.Re1 Rd2+ 31.Kg3 Rd3+ 32.Kf4 Rd4+ 33.Qxd4 Kf7 34.Rxe7+ Qxe7 35.dxe7 {followed shortly by mate}) (24...Rc8 25.Re1 {transposes to above line}) 25.Re1 Bxg2+! 26.Kxg2 Qa8+ 27.Kg1 Rg5+ 28. Kf2 Rf5+ 29.Ke3 Qf3+ 30.Kd2 Qf4+ 31.Kc2 Qxh2+ 32.Kb1 Qxd6 33.Qg8+ Rf8 34.Bf7+ Kd8 35.Qxf8+ Kc7 36.Qxe7 Qxe7 37.Rxe7 Kd6 38.Re4 {A marvellous King walk followed by roughly equal material - but Black's rook is terrible.}) 24.Re1 Bxg2+ 25. Kg1 Rf5 26.Qd4! {Stopping the check from b6} Bf3 27.h3! {Making room for the King} Rc8 28.Kh2 Rc1! (28...Rc4 29.Bxc4 bxc4 30.Qh8+ Rf8 31.Qxh7 Rf7 32.Qg8+ Rf8 33.Qxg6+ Rf7 34.h4! {Black is completely paralysed.}) 29.Qh8+! {Liquidating into a very advantageous ending - possible because the c3-h8 diagonal is now open after move 22!} Rf8 30.Bf7+! Kxf7 31.Rxe7+! Qxe7 32.Qxh7+ Ke6 33.Qxe7+ Kd5 34.Qxf8 1-0
  </code></pre>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-31T06:52:33.827Z
Comments.Text: My initial shallow analysis with Leela agrees that this line looks promising for White.
Comments.UserDisplayName: koedem
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-31T07:54:55.620Z
Comments.Text: Looking some more with different engines, it appears that this is good for White indeed, and that Ng6 is a mistake for that reason. Which is a good find, that appears to be a popular move in that position.
Comments.UserDisplayName: koedem
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-31T11:00:00.477Z
Comments.Text: Esserman - Van Wely (https://www.chessgames.com/perl/chessgame?gid=1630005) is probably the most famous game in this line, and Marc Esserman IM covers this game in detail in his book "Mayhem in the Morra". Unfortunately I am away currently and don't have the book to hand, if I remember when I am home I will check what he says, but he definitely finds it to be sound.
Comments.UserDisplayName: Ian Bush
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-31T11:01:34.527Z
Comments.Text: BTW Lichess doesn't use Elo for its rating system  - it uses Glicko 2 https://lichess.org/page/rating-systems
Comments.UserDisplayName: Ian Bush
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-31T12:25:38.890Z
Comments.Text: @IanBush, yes, Marc's game is mentioned in my annotation of move 15. 17.Bf7 is somewhat simpler than Marc's 17.Bg5.
Comments.UserDisplayName: HTTP 410
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-31T14:58:33.657Z
Comments.Text: @HTTP410: Just curious, am I anywhere mentioned in the book? Decades ago, I often had to fight Hannes+Morra+tons of preparation and find everything over the board, sometimes sufficiently, sometimes not (I firmly believe preparation is for profis and lamers :-)
Comments.UserDisplayName: Hauke Reddmann
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-07T15:25:53.920Z
Comments.Text: @HaukeReddmann Yes, page 101 annotates your Hamburg 2001 loss against Hannes in the aforementioned Nge7 System. It's an interesting game showing two significant errors each for Black and White: 14.f4?! | 15...exf5? | 18.Rdxd5? Bxd5?
Comments.UserDisplayName: HTTP 410
Tags: <opening><theory><sacrifice><smith-morra-gambit>
Title: Is this theoretical novelty double-piece sacrifice actually sound?
ThreadText: # Is this theoretical novelty double-piece sacrifice actually sound?
  
  (Asked by: username_0 on 2021-12-31)
  
  Working my way through Hannes Langrock's book on the modern Morra Gambit (second edition), I came across an interesting sacrifice that he believes is at best worth a draw. Indeed that's also Stockfish's initial conclusion. But when I analyse it for a while (with SF 14.1 on 32 cores), it actually appears to be very strong, maybe even winning. The line starts with 11 Nd5, the critical point is 19 Rxe7, and my novelties are 20 Qe5 and 21 Kh1.
  
  Have I missed something in my notes to the attached analysis, or is this double-piece sac really sound?
  
  *[In case it matters, I hover around Glicko 2200 on Lichess]*
  
  ```
  [Event "Engine Analysis of Zakharov-Gusev (Tula 2001)"]
  [White "SF 14.1"]
  [Black "SF 14.1"]
  [Result "1-0"]
  [ECO "B21"]
  [Annotator "Mark Pearce"]
  [PlyCount "67"]
  [FEN "RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1"]
  
  1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Nf3 Nc6 6.Bc4 a6 7.O-O Nge7 8.Bg5! f6 9.Be3 b5     10.Bb3 Ng6 11.Nd5!? {Zacharov's daring innovation.} exd5 12.exd5 Nce5 (12...Na5? 13.Re1! Be7 14.d6 {Black is in big trouble}) 13.d6! Bb7 14.Nxe5 fxe5 (14...Nxe5? 15.Re1 Qb8 16.Bc5 {Black's position is hopeless}) 15.f4! exf4! (15...Qf6? 16.fxe5 Qxe5 17.Bf7+ Kd8 18.Bb6+ Kc8 19.Re1 {Winning}) 16.Re1! {Zakharov had to foresee this position before he played his sacrifice on move 11!} 16...fxe3 17.Rxe3+ Be7 18.Qd4 Qc8! (18... Qb8? 19.dxe7 Qa7 20.Bf7+! Kxf7 21.e8=Q+ Rhxe8 22.Rf1+ Kg8 23.Qxa7 Rxe3 24.Qxe3 {1-0 Zahkarov-Gusev, Tula 2001}) (18...Rf8? 19.dxe7 Nxe7 20.Rae1 Rf6 21.Qc5! d6 22.Rxe7+ Qxe7 23.Rxe7+ Kxe7 24.Qc7+ {Winning}) 19.Rxe7+! {Already two pieces down, White makes a further sacrifice!} (19.Rae1!? Qc6= {After this more prosaic line Hannes Langrock (in his "Modern Morra Gambit, Second Edition") believes the position looks like a draw, and the 11 games following this line in Chessbase's Mega 2020 database agree - there are 8 draws and only 3 wins for White.}) 19...Nxe7 20.Qe5! (20.Re1? Qc6! 21.Bd5! O-O-O! (21...Qxd5 22.Rxe7+ Kd8 23.Qb6+ Kc8 24. Qc7#) (21...Qxd6 22.Bf7+ Kxf7 23.Qxd6 Rhe8 24.Qxd7!) 22.Bxc6 Nxc6! {This is the only line analysed by Langrock - and White is losing})(20.Qe3? Qd8 21.Re1 a5!=)  20...Qd8 21.Kh1! {A beautifully quiet move that prevents ...Qb6+ and a potential escape with ...0-0-0. This is a crazy position - White has sacrified two pieces for a stranglehold on e7, but surprisingly doesn't need to hurry with exploitation.} 21...Rf8 22.Qh5+! g6 23.Qe5 {White quietly takes time to open the c3-h8 diagonal before doubling on the e-file. This is possible because Black is almost paralysed.} 23...Rf2 (23...Rf5 24.Qg7 Ra7! (24...Be4 25.Re1 Rc8 26.h3 Rc1 27.Rxc1 Bxg2+ 28.Kh2! Bd5 29.Bxd5 Rxd5 30.Re1 Rd2+ 31.Kg3 Rd3+ 32.Kf4 Rd4+ 33.Qxd4 Kf7 34.Rxe7+ Qxe7 35.dxe7 {followed shortly by mate}) (24...Rc8 25.Re1 {transposes to above line}) 25.Re1 Bxg2+! 26.Kxg2 Qa8+ 27.Kg1 Rg5+ 28. Kf2 Rf5+ 29.Ke3 Qf3+ 30.Kd2 Qf4+ 31.Kc2 Qxh2+ 32.Kb1 Qxd6 33.Qg8+ Rf8 34.Bf7+ Kd8 35.Qxf8+ Kc7 36.Qxe7 Qxe7 37.Rxe7 Kd6 38.Re4 {A marvellous King walk followed by roughly equal material - but Black's rook is terrible.}) 24.Re1 Bxg2+ 25. Kg1 Rf5 26.Qd4! {Stopping the check from b6} Bf3 27.h3! {Making room for the King} Rc8 28.Kh2 Rc1! (28...Rc4 29.Bxc4 bxc4 30.Qh8+ Rf8 31.Qxh7 Rf7 32.Qg8+ Rf8 33.Qxg6+ Rf7 34.h4! {Black is completely paralysed.}) 29.Qh8+! {Liquidating into a very advantageous ending - possible because the c3-h8 diagonal is now open after move 22!} Rf8 30.Bf7+! Kxf7 31.Rxe7+! Qxe7 32.Qxh7+ Ke6 33.Qxe7+ Kd5 34.Qxf8 1-0
  
  ```
  
  **Tags:** opening, theory, sacrifice, smith-morra-gambit
  
  > **Comments:**
  > **username_1**: My initial shallow analysis with Leela agrees that this line looks promising for White.  
  > **username_1**: Looking some more with different engines, it appears that this is good for White indeed, and that Ng6 is a mistake for that reason. Which is a good find, that appears to be a popular move in that position.  
  > **username_2**: Esserman - Van Wely (https://www.chessgames.com/perl/chessgame?gid=1630005) is probably the most famous game in this line, and Marc Esserman IM covers this game in detail in his book "Mayhem in the Morra". Unfortunately I am away currently and don't have the book to hand, if I remember when I am home I will check what he says, but he definitely finds it to be sound.  
  > **username_2**: BTW Lichess doesn't use Elo for its rating system  - it uses Glicko 2 https://lichess.org/page/rating-systems  
  > **username_0**: @username_2, yes, Marc's game is mentioned in my annotation of move 15. 17.Bf7 is somewhat simpler than Marc's 17.Bg5.  
  > **username_3**: @username_0: Just curious, am I anywhere mentioned in the book? Decades ago, I often had to fight Hannes+Morra+tons of preparation and find everything over the board, sometimes sufficiently, sometimes not (I firmly believe preparation is for profis and lamers :-)  
  > **username_0**: @username_3 Yes, page 101 annotates your Hamburg 2001 loss against Hannes in the aforementioned Nge7 System. It's an interesting game showing two significant errors each for Black and White: 14.f4?! | 15...exf5? | 18.Rdxd5? Bxd5?  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_4 on 2021-12-31. Score: 6
  
  I found the following game, which reaches the position at move 19 by transposition. It also indicates that the sacrifice is sound, with the continuation 20. Qe3
  
  ```
  [Event "It"]
  [Site "St. Lo (France)"]
  [Date "2012.07.10"]
  [Round "5"]
  [White "Devallee, Jeremie (FRA)"]
  [Black "Duchateau, Thomas (FRA)"]
  [Result "1-0"]
  [Eco "B21"]
  [Annotator ""]
  [Source ""]
  [Startply "39"]
  [FEN ""]
  
  1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 e6 5.Nf3 a6 6.Bc4 Ne7 7.Bg5 f6 8.Be3 Ng6 9.O-O b5 10.Bb3 Nc6 11.Nd5 exd5 12.exd5 Nce5 13.Nxe5 fxe5 14.d6 Bb7 15.f4 exf4 16.Re1 fxe3 17.Rxe3+ Be7 18.Qd4 Qc8 19.Rxe7+ Nxe7 20.Qe3 Qd8 21.Re1 Rc8 22.Qd4 Qa5 23.Rxe7+ Kd8 24.Re8+ 1-0
  
  ```
  
  > **Comments:**
  > **username_0**: Nice find! Devallee's 20.Qe3!? (instead of my 20.Qe5) prevents Black's check on b6, but SF can't find any winning line for White here because the Queen's placement on e3 (no access to g7 or h5) isn't as threatening as on e5. Duchateau's 21...Rc8?! looks like a minor mistake, and 22...Qa5?? is a huge blunder.  
  > **username_0**: According to SF, the best line for Black is 20...Qd8 21.Re1 a5! and that leads to an approximately equal position. White has enough compensation for the sacrifices, but no more.  
  
  ---
  
  