Answers.Body: <p>The pawn is only temporarily sacrificed. Black can regain it tactically after a few moves, although it's not readily obvious how that happens. It should be mentioned that instead of 11...c4, 11...Qa5 which prepares c4, is a completely fine move. Here I provide a few sample variations that show what happens if White desperately tries to hold on to the extra pawn.</p>
  <pre><code>[FEN &quot;&quot;]
  [StartFlipped &quot;1&quot;]
  
  1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Bd3 Bg7 8. Nge2 O-O 9. O-O Nbd7 10. f4 a6 
  11. a4 c4 (11... Qa5 {is a fine move, preparing c4. For example} 12. Ra3 c4 {and now the pawn cannot be taken without seriously compromising White's position} 
  13. Bxc4 $2 Qc5+ 14. Qd4 Nxe4 $1 $15) 12. Bxc4 Re8 {and it is difficult for White to hold on to the extra pawn. For example}
  13. Ng3 Nc5 14. Bd3 $6 (14. Re1 $6 h5 15. e5 dxe5 16. fxe5 $2 
  (16. f5 {is better}) 16... Ng4 17. e6 Bxe6 18. dxe6 Bd4+ $19) 
  (14. e5 $1 dxe5 15. f5 $1 $14 {is good.}) 
  14... h5 {threatening h4, which undermines the g3 knight that
  defends e4. There's not much that White can do about it.} 
  15. h4 $4 ({Admitting the mistake with} 15. f5 {is better} h4 
  16. Nh1 Ncxe4 17. fxg6 Qb6+ 18. Nf2 fxg6 $15) 
  15... Ng4 $19 {and now h4 falls and with it the game as well.} *
  </code></pre>
  <p>The idea behind the sacrifice is to simply mobilize Black's pieces. The Black knight wants to come to c5 and pressure e4. Then the rook can join in from e8 to attack e4 as well. That also makes the knight on f6 more effective, and so on...</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-28T21:25:32.667Z
Answers.LastActivityDate: 2023-01-28T21:38:33.273Z
Answers.LastEditDate: 2023-01-28T21:38:33.273Z
Answers.UserDisplayName: NM Wesley Falcao
Body: <p>Consider the following line</p>
  <pre><code>[FEN &quot;&quot;]
  [StartPly &quot;23&quot;]
  [StartFlipped &quot;1&quot;]
  
  1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Bd3 Bg7 8. Nge2 O-O 9. O-O Nbd7 10. f4 a6 11. a4
  </code></pre>
  <p>Stockfish says that <strong>c4</strong> is the best move here. The line then proceeds normally, as if nothing happened, with <strong>12. Re8</strong></p>
  <p>I know that the general game plan is to expand on the queen side, but I don't see why this pawn sacrifice is so necessary.</p>
  <p>What is the idea behind this sacrifice then?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-08-06T20:30:44.547Z
Comments.Text: this is a thematic idea that comes with kid 4 pawns attack lines. it also brings out Nc5 and with Re8 pressuring on e4. in benoni lines whites d5 becomes a target once e4 is gone.
Comments.UserDisplayName: cmgchess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-08-06T20:33:18.317Z
Comments.Text: similar line https://lichess.org/analysis/standard/r1bqr1k1/pp1n1pbp/3p1np1/2pP4/4PP2/2N5/PP1NB1PP/R1BQ1RK1_b_-_-_4_11
Comments.UserDisplayName: cmgchess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-08-07T11:04:11.177Z
Comments.Text: As was mentioned earlier in this comment thread, this is a very important thematic idea in the Benoni. Black is pretty cramped and needs good squares for their pieces. ...c5-c4 frees up black's position for a mere pawn, gives an excellent square for black's knight on c5 (from where it can attack white's pawn on e4), opens a diagonal against white's king, clears the c-file of pawns, etc. If you play the Benoni, the ...c5-c4 break is absolutely essential to know about.
Comments.UserDisplayName: Scounged
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-08-07T11:18:48.670Z
Comments.Text: @Scounged I agree. Thanks for the elaboration!
Comments.UserDisplayName: DatBoi
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-01-28T22:38:01.317Z
Comments.Text: Is b3 an option for White if Black doens't make the pawn sacrifice immediately?
Comments.UserDisplayName: David
Tags: <sacrifice><modern-benoni><benoni>
Title: c5-c4 pawn sacrifice in Benoni line
ThreadText: # c5-c4 pawn sacrifice in Benoni line
  
  (Asked by: username_0 on 2022-08-06)
  
  Consider the following line
  [FEN ""]
  [StartPly "23"]
  [StartFlipped "1"]
  
  1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Bd3 Bg7 8. Nge2 O-O 9. O-O Nbd7 10. f4 a6 11. a4
  
  Stockfish says that c4 is the best move here. The line then proceeds normally, as if nothing happened, with 12. Re8
  I know that the general game plan is to expand on the queen side, but I don't see why this pawn sacrifice is so necessary.
  What is the idea behind this sacrifice then?
  
  **Tags:** sacrifice, modern-benoni, benoni
  
  > **Comments:**
  > **username_1**: this is a thematic idea that comes with kid 4 pawns attack lines. it also brings out Nc5 and with Re8 pressuring on e4. in benoni lines whites d5 becomes a target once e4 is gone.  
  > **username_1**: similar line https://lichess.org/analysis/standard/r1bqr1k1/pp1n1pbp/3p1np1/2pP4/4PP2/2N5/PP1NB1PP/R1BQ1RK1_b_-_-_4_11  
  > **username_2**: As was mentioned earlier in this comment thread, this is a very important thematic idea in the Benoni. Black is pretty cramped and needs good squares for their pieces. ...c5-c4 frees up black's position for a mere pawn, gives an excellent square for black's knight on c5 (from where it can attack white's pawn on e4), opens a diagonal against white's king, clears the c-file of pawns, etc. If you play the Benoni, the ...c5-c4 break is absolutely essential to know about.  
  > **username_0**: @username_2 I agree. Thanks for the elaboration!  
  > **username_3**: Is b3 an option for White if Black doens't make the pawn sacrifice immediately?  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_4 on 2023-01-28. Score: 2
  
  The pawn is only temporarily sacrificed. Black can regain it tactically after a few moves, although it's not readily obvious how that happens. It should be mentioned that instead of 11...c4, 11...Qa5 which prepares c4, is a completely fine move. Here I provide a few sample variations that show what happens if White desperately tries to hold on to the extra pawn.
  [FEN ""]
  [StartFlipped "1"]
  
  1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Bd3 Bg7 8. Nge2 O-O 9. O-O Nbd7 10. f4 a6 
  11. a4 c4 (11... Qa5 {is a fine move, preparing c4. For example} 12. Ra3 c4 {and now the pawn cannot be taken without seriously compromising White's position} 
  13. Bxc4 $2 Qc5+ 14. Qd4 Nxe4 $1 $15) 12. Bxc4 Re8 {and it is difficult for White to hold on to the extra pawn. For example}
  13. Ng3 Nc5 14. Bd3 $6 (14. Re1 $6 h5 15. e5 dxe5 16. fxe5 $2 
  (16. f5 {is better}) 16... Ng4 17. e6 Bxe6 18. dxe6 Bd4+ $19) 
  (14. e5 $1 dxe5 15. f5 $1 $14 {is good.}) 
  14... h5 {threatening h4, which undermines the g3 knight that
  defends e4. There's not much that White can do about it.} 
  15. h4 $4 ({Admitting the mistake with} 15. f5 {is better} h4 
  16. Nh1 Ncxe4 17. fxg6 Qb6+ 18. Nf2 fxg6 $15) 
  15... Ng4 $19 {and now h4 falls and with it the game as well.} *
  
  The idea behind the sacrifice is to simply mobilize Black's pieces. The Black knight wants to come to c5 and pressure e4. Then the rook can join in from e8 to attack e4 as well. That also makes the knight on f6 more effective, and so on...
  
  
  ---
  
  