Answers.Body: <p>After retaking the bishop, Black will take on d4 with his pawn, attacking the pinned knight. White can do nothing to stop Black from capturing it &quot;for free&quot; on the next move.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-04T16:26:06.090Z
Answers.LastActivityDate: 2022-03-04T16:26:06.090Z
Answers.UserDisplayName: David
Answers.Body: <p>After you complete the puzzle, &quot;
  Stockfish 14+NNUE
  in local browser&quot; appears in the upper right (just above the list of moves), and a toggle button appears to the right of that. If you click it, it will suggest the continuation 10. Bd2, but you can play around with other lines by making those moves on the board. For instance, after 10. gxf3, the engine recommends 10. ... cxd4. As it has been captured, the knight is not available to capture the pawn, and the queen is deterred by the bishop on g7. As the knight is pinned, it can't be moved away.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-04T20:49:27.273Z
Answers.LastActivityDate: 2022-03-07T02:44:31.937Z
Answers.LastEditDate: 2022-03-07T02:44:31.937Z
Answers.UserDisplayName: Acccumulation
Answers.Body: <p>Here's why:</p>
  <pre><code>[FEN &quot;rn2k1nr/1b1pppbp/8/q1p5/3P4/2N2N2/PP2PPPP/R1BQKB1R b KQkq - 1 1&quot;]
  
  1...Bxf3 2. exf3 cxd4 3. Bd2 (3. Qxd4 Bxd4) dxc3 4. bxc3 Bxc3 5. Rc1 Bxd2+ 6. Qxd2 Qxd2+ 7. Kxd2 Rxa2+ 8.Ke3 Nc6
  </code></pre>
  <p>White is completely lost.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-04T20:16:59.320Z
Answers.Text: True. I can relate to the OP's confusion though: lichess puzzles are often the most puzzling in where they stop and consider it done - sometimes you would just play the move that feels right and it says "congratulations, you won!" all while you sit there stumped.
Answers.UserDisplayName: Lodinn
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-04T20:41:23.810Z
Answers.Text: @Lodinn: For those of us with lower ratings, there's also the problem that in our practical experience, a "good" move is a move which is not a blunder, rather than an actual good move.
Answers.UserDisplayName: Kevin
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-04T23:07:11.507Z
Answers.Text: @Lodinn sometimes it feels like it's saying "yes you get the idea, no need to make you play out the rest of the obvious moves" which in my experience is correct maybe 50% of the time
Answers.UserDisplayName: llama
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-05T04:36:41.890Z
Answers.Text: @llama I think that more often, it's really saying "Yes, now there's a few ways to win from here, but we have a strict requirement that there is exactly one correct solution to our puzzles so the puzzle must end here"
Answers.UserDisplayName: Edward
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-05T08:38:27.460Z
Answers.Text: Subtract one point for not taking a2 with check before Nc6 :-)
Answers.UserDisplayName: Hauke Reddmann
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-06T22:42:38.420Z
Answers.Text: @HaukeReddmann wait, what?
Answers.UserDisplayName: Michael
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-07T07:32:58.723Z
Answers.Text: @Michael: That was a joke referring to the playing style of computers (and consequently, the sometimes strange way such puzzles are evaluated). At the end of Brian's variant, Nc6 (or something else, but Nc6 is obvious and best) is absolutely needed to stop White from Rc8#. But since taking the pawn is more gratis material, and the check hinders Rc8# for a move, a computer would complain about immediate Nc6.
Answers.UserDisplayName: Hauke Reddmann
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-03-04T16:41:32.603Z
Answers.LastActivityDate: 2022-03-06T23:08:11.350Z
Answers.LastEditDate: 2022-03-06T23:08:11.350Z
Answers.UserDisplayName: Brian Towers
Body: <p>In this <a href="https://lichess.org/training/Y4tuf" rel="noreferrer">Lichess puzzle</a>, after the initial moves</p>
  <pre><code>[title &quot;Black to move&quot;]
  [fen &quot;&quot;]
  [Startply &quot;17&quot;]
  [StartFlipped &quot;1&quot;]
  
  1. c4 b5 2. cxb5 Bb7 3. Nf3 g5 4. Nxg5 Bg7 5. Nf3 c5 6. Nc3 a6 7. d4 axb5 8. Nxb5 Qa5+ 9. Nc3 Bxf3!
  </code></pre>
  <p>Why can the bishop just take the knight? Why is it so bad for white to retake on f3?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-03-04T12:09:53.010Z
Comments.Text: 1. if you play Bxf3 first then exf3 opens up the f1 bishop guarding the b5 knight. so Qa5 doesnt work anymore due to Bd2. 2.if Qa5 first the Nc3 is forced because otheriwise it is hanging. Now if Bxf3 white doesnt really have a choice other than to take back. then a defender is removed from d4 so black can take cxd4 and win the c3 knight due to pin
Comments.UserDisplayName: cmgchess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-03-04T12:16:43.627Z
Comments.Text: If white takes bishop, theb b cxd4 and taking the knight next move
Comments.UserDisplayName: Arctic Char
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-03-04T15:29:16.070Z
Comments.Text: The meaning of my question seems to have got lost during editing (now restored). I didn't want to give the puzzle away, but I was apparently not clear enough initially.
Comments.UserDisplayName: hkBst
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-03-04T15:37:04.153Z
Comments.Text: @cmgchess, you would think that taking back the bishop was a no-brainer, but the computer thinks it is very bad to do that (with either pawn). The computer thinks the solution is to take the knight and then for white to play Bd2, and then black can move its bishop away. If you take on f3 then the eval goes down more than 3 points!
Comments.UserDisplayName: hkBst
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-03-04T15:48:38.213Z
Comments.Text: @hkBst i mean even if he didnt take back and played Bd2 he'll be down a piece for no compensation after black retreats the bishop.
Comments.UserDisplayName: cmgchess
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-03-06T06:03:44.763Z
Comments.Text: The bishop CAN take the knight because the bishop is directly attacking the knight.  It's a perfectly valid and legal move.  I think you probably meant to ask `Why SHOULD the bishop take the knight?`
Comments.UserDisplayName: JK.
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-03-06T15:00:42.973Z
Comments.Text: @JK. not "can take", but "can just take", as in "without any consequences" or "as if the knight is hanging". I think that is correctly implied, and different from "should take".
Comments.UserDisplayName: hkBst
Tags: <analysis><puzzles>
Title: Why can the bishop just take the knight in this Lichess puzzle?
ThreadText: # Why can the bishop just take the knight in this Lichess puzzle?
  
  (Asked by: username_0 on 2022-03-04)
  
  In this [Lichess puzzle](https://lichess.org/training/Y4tuf), after the initial moves
  
  ```
  [title "Black to move"]
  [fen ""]
  [Startply "17"]
  [StartFlipped "1"]
  
  1. c4 b5 2. cxb5 Bb7 3. Nf3 g5 4. Nxg5 Bg7 5. Nf3 c5 6. Nc3 a6 7. d4 axb5 8. Nxb5 Qa5+ 9. Nc3 Bxf3!
  
  ```
  
  Why can the bishop just take the knight? Why is it so bad for white to retake on f3?
  
  **Tags:** analysis, puzzles
  
  > **Comments:**
  > **username_1**: 1. if you play Bxf3 first then exf3 opens up the f1 bishop guarding the b5 knight. so Qa5 doesnt work anymore due to Bd2. 2.if Qa5 first the Nc3 is forced because otheriwise it is hanging. Now if Bxf3 white doesnt really have a choice other than to take back. then a defender is removed from d4 so black can take cxd4 and win the c3 knight due to pin  
  > **username_2**: If white takes bishop, theb b cxd4 and taking the knight next move  
  > **username_0**: The meaning of my question seems to have got lost during editing (now restored). I didn't want to give the puzzle away, but I was apparently not clear enough initially.  
  > **username_0**: @username_1, you would think that taking back the bishop was a no-brainer, but the computer thinks it is very bad to do that (with either pawn). The computer thinks the solution is to take the knight and then for white to play Bd2, and then black can move its bishop away. If you take on f3 then the eval goes down more than 3 points!  
  > **username_1**: @username_0 i mean even if he didnt take back and played Bd2 he'll be down a piece for no compensation after black retreats the bishop.  
  > **username_3**: The bishop CAN take the knight because the bishop is directly attacking the knight.  It's a perfectly valid and legal move.  I think you probably meant to ask `Why SHOULD the bishop take the knight?`  
  > **username_0**: @JK. not "can take", but "can just take", as in "without any consequences" or "as if the knight is hanging". I think that is correctly implied, and different from "should take".  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_6 on 2022-03-04. Score: 10 | Accepted answer
  
  Here's why:
  
  ```
  [FEN "rn2k1nr/1b1pppbp/8/q1p5/3P4/2N2N2/PP2PPPP/R1BQKB1R b KQkq - 1 1"]
  
  1...Bxf3 2. exf3 cxd4 3. Bd2 (3. Qxd4 Bxd4) dxc3 4. bxc3 Bxc3 5. Rc1 Bxd2+ 6. Qxd2 Qxd2+ 7. Kxd2 Rxa2+ 8.Ke3 Nc6
  
  ```
  
  White is completely lost.
  
  > **Comments:**
  > **username_7**: True. I can relate to the OP's confusion though: lichess puzzles are often the most puzzling in where they stop and consider it done - sometimes you would just play the move that feels right and it says "congratulations, you won!" all while you sit there stumped.  
  > **username_8**: @username_7: For those of us with lower ratings, there's also the problem that in our practical experience, a "good" move is a move which is not a blunder, rather than an actual good move.  
  > **username_9**: @username_7 sometimes it feels like it's saying "yes you get the idea, no need to make you play out the rest of the obvious moves" which in my experience is correct maybe 50% of the time  
  > **username_10**: @username_9 I think that more often, it's really saying "Yes, now there's a few ways to win from here, but we have a strict requirement that there is exactly one correct solution to our puzzles so the puzzle must end here"  
  > **username_11**: Subtract one point for not taking a2 with check before Nc6 :-)  
  > **username_12**: @username_11 wait, what?  
  > **username_11**: @username_12: That was a joke referring to the playing style of computers (and consequently, the sometimes strange way such puzzles are evaluated). At the end of username_6's variant, Nc6 (or something else, but Nc6 is obvious and best) is absolutely needed to stop White from Rc8#. But since taking the pawn is more gratis material, and the check hinders Rc8# for a move, a computer would complain about immediate Nc6.  
  
  ---
  
  ### Answer by username_4 on 2022-03-04. Score: 8
  
  After retaking the bishop, Black will take on d4 with his pawn, attacking the pinned knight. White can do nothing to stop Black from capturing it "for free" on the next move.
  
  
  ---
  
  ### Answer by username_5 on 2022-03-04. Score: 7
  
  After you complete the puzzle, "
  Stockfish 14+NNUE
  in local browser" appears in the upper right (just above the list of moves), and a toggle button appears to the right of that. If you click it, it will suggest the continuation 10. Bd2, but you can play around with other lines by making those moves on the board. For instance, after 10. gxf3, the engine recommends 10. ... cxd4. As it has been captured, the knight is not available to capture the pawn, and the queen is deterred by the bishop on g7. As the knight is pinned, it can't be moved away.
  
  
  ---
  
  