Answers.Body: <p>Contrary to the assertion of @Evargalo, the Dekker gambit is far from a blunder! In fact, the tactical possibilities for White are excellent. Black Najdorf players are taken out-of-book and even strong players can lose quickly.</p>
  <p>Briefly:</p>
  <ul>
  <li>After 6...e6, the position transposes to the <code>Keres</code> or <code>Perenyi</code> attack</li>
  <li>After 6...Bxg4 (surely the best response), the g-file is open for White which discourages kingside castling. In the hundreds of games I've played, Black usually chooses queenside castling when the g7 pawn needs protection as well as the weakened dark squares on the Black queenside. Note that the capture is not &quot;with tempo&quot; as White will respond with 7.f3 (see next point) which stabilises the centre.</li>
  <li>After 6...Bxg4 7.f3 (definitely the best for White), the e4 pawn is protected. This allows White to attack with a more stable centre.</li>
  <li>After 6...Bxg4 7.f3 Bd7 I recommend 8.Bg5. Later after ...h6, the bishop can retreat to e3. Together with the queen, White can target h6 or (with the Queen on f2) the weakened dark squares on the queenside.</li>
  <li>The response 6...Bxg4 7.f3 Bh5 is harder to meet, but the Black bishop can be offside on h5/g6</li>
  <li>After 6...Nxg4, White can respond with 7.Be2 with the option of playing f2-f4 in one move.</li>
  <li>For a small theoretical advantage to Black, White achieves open, stable play. Plans are easy to understand for White and Black is out-of-book. Not optimal against a super-computer, but as a human what is...?</li>
  </ul>
  <h3>Aside</h3>
  <p>I am World Champion at a number of board games, amongst them Entropy, Pacru, and Lines of Action. At chess, I am only intermediate strength (~2100 Elo), though have beaten or drawn several IMs.</p>
  <p>The Dekker gambit (6.g4!?) was discovered independently in 1997/8 while trying out a Keres-style attack. I wrote an article on the opening for <code>Chess</code> in 1999, and had a chance to discuss briefly with Kasparov at a book-signing in London. Later I lobbied for the opening to be officially named after myself in the early 2000s. Subsequently I discovered that the opening has been played by other (stronger) players in the past, though inconsistently.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-08-15T17:22:59.803Z
Answers.Text: Not every day that the namesake of an opening chimes in here. Do you have any instructive games that you could point to in this line?
Answers.UserDisplayName: Awalrod
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Answers.UserDisplayName: AlainD
Answers.Body: <p>If Black actually plans to play e6 after a6 anyways, White can play 6. Be3 e6 7.g4. Apart from normally looking h6, Black can respond with 7...e5, and since White cannot exchange the threatening bishop with Bb5+ and is ahead in development, decides to sacrifice the knight with 8. Nf5 g6, leading to Hungarian attack <a href="https://en.wikipedia.org/wiki/Sicilian_Defence,_Najdorf_Variation#English_Attack:_6.Be3" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Sicilian_Defence,_Najdorf_Variation#English_Attack:_6.Be3</a> . From what I remember, it has not been refuted yet.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-04T08:06:20.153Z
Answers.Text: I think this attack is mostly known as "Perenyi attack". ASAIU, it is considered a forced draw now that supercomputers are used for extensive analysis, and thus it has alas vanished from GM practice.
Answers.UserDisplayName: Evargalo
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Answers.UserDisplayName: Ferazhu
Answers.Body: <p>In the Najdorf variation (1.e4 c5 2.Nf3 d6 3.d4 cd4 4.Nxd4 Nf6 5.Nc3 a6), the c8-h3 diagonal remains open and Black has two hits (Nf6, Bc8) on the square g4. If White plays 6.g4?? in the spirit of the Keres attack, Black already gets a decisive advantage with 6...Bxg4, grabing a free pawn with tempo.</p>
  <p>In contrast, the Keres variation 6.g4!? is possible against the Scheveningen because 5...e6 (or 2...e6 is Black chose another move order) blocked the Bc8 diagonal and reduced their control of g4: then 6...Nxg4?? 7.Qxg4 e5 8.Nf5 g6 9.Bc4 would be winning for White.</p>
  <p><em>Edit Feb 2022</em> :
  In spite of the loss of a pawn, some players are toying with the idea of playing 6.g4? against the Najdorf anyway. World Blitz Champion Maxime Vachier-Lagrave used it in a <a href="https://twitter.com/manutiss/status/1492445838018326530" rel="nofollow noreferrer">demo bullet game</a> against GM Bilel Bellahcene, live on French TV. Bellahcene quips: &quot;hey, you're using my own variation!&quot;</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-03T16:39:47.787Z
Answers.Text: Thanks, I never thought to look at the diagonal.
Answers.UserDisplayName: user31736
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-01-03T16:50:29.513Z
Answers.Text: What would be the best move be after f3 for white and how would it be winning for Black.
Answers.UserDisplayName: user31736
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Answers.CreationDate: 2022-01-03T19:48:03.150Z
Answers.Text: @user31736: A quick check on LiChess gave that g4 is called Dekker gambit, only 2 master games exist and the computer prefers Lh5, -0.9 (i.e. exactly the sacrificed pawn).
Answers.UserDisplayName: Hauke Reddmann
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-08-15T10:03:45.710Z
Answers.Text: As the namesake of the Dekker gambit (Alain Dekker, South Africa), 6.g4!? is a speculative pawn sacrifice and certainly `not` a blunder! The sacrifice opens the g-file and after 6...Bxg4 7.f3 supports the e4 pawn allowing White to attack quickly. with greater central stability The gambit is rare but definitely playable.
Answers.UserDisplayName: AlainD
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Answers.LastActivityDate: 2022-02-16T09:36:10.337Z
Answers.LastEditDate: 2022-02-16T09:36:10.337Z
Answers.UserDisplayName: Evargalo
Body: <p>Recently I've been looking into the Scheveningen variation of the Sicilian and from what I have read it seems like the Keres attack is a big threat and you need great calculation ability to stop it as Black. This is why numerous books have recommended just playing the Najdorf and then e6 on the 6th move saying that the Najdorf (a6) stops the Keres attack.</p>
  <p>My question is how the move a6 stops the Keres attack. If I could have a specific game or something since I can't find a concrete answer anywhere else.</p>
  
Tags: <sicilian-defense>
Title: How does the Najdorf variation of the Sicilian defense stop the Keres attack?
ThreadText: # How does the Najdorf variation of the Sicilian defense stop the Keres attack?
  
  (Asked by: username_0 on 2022-01-03)
  
  Recently I've been looking into the Scheveningen variation of the Sicilian and from what I have read it seems like the Keres attack is a big threat and you need great calculation ability to stop it as Black. This is why numerous books have recommended just playing the Najdorf and then e6 on the 6th move saying that the Najdorf (a6) stops the Keres attack.
  
  My question is how the move a6 stops the Keres attack. If I could have a specific game or something since I can't find a concrete answer anywhere else.
  
  **Tags:** sicilian-defense
  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_4 on 2022-01-03. Score: 9 | Accepted answer
  
  In the Najdorf variation (1.e4 c5 2.Nf3 d6 3.d4 cd4 4.Nxd4 Nf6 5.Nc3 a6), the c8-h3 diagonal remains open and Black has two hits (Nf6, Bc8) on the square g4. If White plays 6.g4?? in the spirit of the Keres attack, Black already gets a decisive advantage with 6...Bxg4, grabing a free pawn with tempo.
  
  In contrast, the Keres variation 6.g4!? is possible against the Scheveningen because 5...e6 (or 2...e6 is Black chose another move order) blocked the Bc8 diagonal and reduced their control of g4: then 6...Nxg4?? 7.Qxg4 e5 8.Nf5 g6 9.Bc4 would be winning for White.
  
  *Edit Feb 2022* :
  In spite of the loss of a pawn, some players are toying with the idea of playing 6.g4? against the Najdorf anyway. World Blitz Champion Maxime Vachier-Lagrave used it in a [demo bullet game](https://twitter.com/manutiss/status/1492445838018326530) against GM Bilel Bellahcene, live on French TV. Bellahcene quips: "hey, you're using my own variation!"
  
  > **Comments:**
  > **username_0**: Thanks, I never thought to look at the diagonal.  
  > **username_0**: What would be the best move be after f3 for white and how would it be winning for Black.  
  > **username_5**: @username_0: A quick check on LiChess gave that g4 is called Dekker gambit, only 2 master games exist and the computer prefers Lh5, -0.9 (i.e. exactly the sacrificed pawn).  
  > **username_1**: As the namesake of the Dekker gambit (Alain Dekker, South Africa), 6.g4!? is a speculative pawn sacrifice and certainly `not` a blunder! The sacrifice opens the g-file and after 6...Bxg4 7.f3 supports the e4 pawn allowing White to attack quickly. with greater central stability The gambit is rare but definitely playable.  
  
  ---
  
  ### Answer by username_1 on 2024-08-15. Score: 5
  
  Contrary to the assertion of @username_4, the Dekker gambit is far from a blunder! In fact, the tactical possibilities for White are excellent. Black Najdorf players are taken out-of-book and even strong players can lose quickly.
  
  Briefly:
  
  * After 6...e6, the position transposes to the `Keres` or `Perenyi` attack
  * After 6...Bxg4 (surely the best response), the g-file is open for White which discourages kingside castling. In the hundreds of games I've played, Black usually chooses queenside castling when the g7 pawn needs protection as well as the weakened dark squares on the Black queenside. Note that the capture is not "with tempo" as White will respond with 7.f3 (see next point) which stabilises the centre.
  * After 6...Bxg4 7.f3 (definitely the best for White), the e4 pawn is protected. This allows White to attack with a more stable centre.
  * After 6...Bxg4 7.f3 Bd7 I recommend 8.Bg5. Later after ...h6, the bishop can retreat to e3. Together with the queen, White can target h6 or (with the Queen on f2) the weakened dark squares on the queenside.
  * The response 6...Bxg4 7.f3 Bh5 is harder to meet, but the Black bishop can be offside on h5/g6
  * After 6...Nxg4, White can respond with 7.Be2 with the option of playing f2-f4 in one move.
  * For a small theoretical advantage to Black, White achieves open, stable play. Plans are easy to understand for White and Black is out-of-book. Not optimal against a super-computer, but as a human what is...?
  
  ### Aside
  
  I am World Champion at a number of board games, amongst them Entropy, Pacru, and Lines of Action. At chess, I am only intermediate strength (~2100 Elo), though have beaten or drawn several IMs.
  
  The Dekker gambit (6.g4!?) was discovered independently in 1997/8 while trying out a Keres-style attack. I wrote an article on the opening for `Chess` in 1999, and had a chance to discuss briefly with Kasparov at a book-signing in London. Later I lobbied for the opening to be officially named after myself in the early 2000s. Subsequently I discovered that the opening has been played by other (stronger) players in the past, though inconsistently.
  
  > **Comments:**
  > **username_2**: Not every day that the namesake of an opening chimes in here. Do you have any instructive games that you could point to in this line?  
  
  ---
  
  ### Answer by username_3 on 2022-01-04. Score: 0
  
  If Black actually plans to play e6 after a6 anyways, White can play 6. Be3 e6 7.g4. Apart from normally looking h6, Black can respond with 7...e5, and since White cannot exchange the threatening bishop with Bb5+ and is ahead in development, decides to sacrifice the knight with 8. Nf5 g6, leading to Hungarian attack <https://en.wikipedia.org/wiki/Sicilian_Defence,_Najdorf_Variation#English_Attack:_6.Be3> . From what I remember, it has not been refuted yet.
  
  > **Comments:**
  > **username_4**: I think this attack is mostly known as "Perenyi attack". ASAIU, it is considered a forced draw now that supercomputers are used for extensive analysis, and thus it has alas vanished from GM practice.  
  
  ---
  
  