Answers.Body: <p><code>Bxf2+</code> gives away all your advantage because of the precise line you mention. The correct move is <code>e5</code> (to protect your bishop with tempo, note <code>1...e5 2.O-O exf4 3.Qxd4</code> doesn't work because of <code>Ne2+</code> fork), followed by <code>Ba6</code>, preventing castling and attacking the trapped <code>a8</code> bishop. Notice <code>Bc6-Bd7-Bg4</code> doesn't really save the bishop as shown below: (covering some side-variations as well, rather called for as it's a very concrete position)</p>
  
  <pre><code> [title "1...e5"]
   [fen "B1b2rk1/p3pp1p/6p1/q1Pp4/3b1B2/2n4P/P2Q1PP1/2R1K2R b KQq - 0 1"]
  
   1...e5 (1...Qxc5 {also a good move with similar threats except the queen discovery} 2.O-O Ba6 3.Rfe1 Rxa8 4.Be3 Bxe3 5.Rxe3 d4 {easily winning: two pieces and a pawn for the rook, together with a passed pawn and dominant knight}) (1...Ba6 {The immediate Ba6 is not good enough probably but it's a fun line, the idea with Ne2+ forking bishop and knight while still taking on a8.} 2.Qxd4 Ne2+ 3.Qd2 Qxd2+ 4.Kxd2 Rxa8 5.Be3 Nxc1 6.Rxc1 {still a pawn up but it's opposite colored-bishop so always big drawing chances.}) 2.Bh6 Ba6 3.Bc6 (3.Bxd5 Rd8 4.Bf3 Bxf2+ {wins on the spot for black}) (3.Bxf8 Bxf2+ {however white recaptures loses on the spot} 4.Kxf2 Ne4+) Rc8 4.Bd7 Rxc5 5.Bg4 Bxf2+ 6.Qxf2 Ne4+ {and you're winning the house.}
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-25T14:48:31.260Z
Answers.Text: We protect our bishop with tempo, but then what are the following ideas?
Answers.UserDisplayName: Jossie Calderon
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-25T14:52:58.383Z
Answers.Text: I've shown the main variation in the diagram. You keep the king in center, you take the trapped `a8` bishop, you have huge central space with two active minor pieces + a pawn for white's out of play rook on `h1,` so white's clearly losing. This position is not so much about ideas but concrete assessment in order to convert black's advantage, hence the diagram and discussion of side-lines.
Answers.UserDisplayName: Ellie
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-25T15:44:35.733Z
Answers.Text: A sideline to add is 3.Bxf8 (by far the most natural move) which loses to the same 3...Bxf2!
Answers.UserDisplayName: Evargalo
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-25T15:50:59.800Z
Answers.Text: @Evargalo Yes indeed, added.
Answers.UserDisplayName: Ellie
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-25T14:42:43.483Z
Answers.LastActivityDate: 2018-01-25T15:53:44.637Z
Answers.LastEditDate: 2018-01-25T15:53:44.637Z
Answers.UserDisplayName: Ellie
Body: <pre><code>B1b2rk1/p3pp1p/6p1/q1Pp4/3b1B2/2n4P/P2Q1PP1/2R1K2R b K - 0 17
  </code></pre>
  
  <p>Stockfish rates this position as -2.94, so Black is clearly winning. Or is it so clear? After 1... Bxf2+ 2. Qxf2 Ne4+ 3. Bd2 Nxf2 4. Bxa5 Nxh1 5. Bxd5, White obtains the Bishop pair in an open position and a passed pawn. This is not the winning move. (Actually, there are two: The alternative is 1... Qxc5.)</p>
  
  <p>However, I cannot fathom how Black is better. Sure, material is even in terms of points, the White LSB is locked in and eventually Ba6 will be played, but when is <em>eventually</em> and how?</p>
  
Tags: <tactics>
Title: What is the winning move here and why?
ThreadText: # What is the winning move here and why?
  
  (Asked by: username_0 on 2018-01-25)
  
  B1b2rk1/p3pp1p/6p1/q1Pp4/3b1B2/2n4P/P2Q1PP1/2R1K2R b K - 0 17
  
  Stockfish rates this position as -2.94, so Black is clearly winning. Or is it so clear? After 1... Bxf2+ 2. Qxf2 Ne4+ 3. Bd2 Nxf2 4. Bxa5 Nxh1 5. Bxd5, White obtains the Bishop pair in an open position and a passed pawn. This is not the winning move. (Actually, there are two: The alternative is 1... Qxc5.)
  However, I cannot fathom how Black is better. Sure, material is even in terms of points, the White LSB is locked in and eventually Ba6 will be played, but when is eventually and how?
  
  **Tags:** tactics
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2018-01-25. Score: 4 | Accepted answer
  
  Bxf2+ gives away all your advantage because of the precise line you mention. The correct move is e5 (to protect your bishop with tempo, note 1...e5 2.O-O exf4 3.Qxd4 doesn't work because of Ne2+ fork), followed by Ba6, preventing castling and attacking the trapped a8 bishop. Notice Bc6-Bd7-Bg4 doesn't really save the bishop as shown below: (covering some side-variations as well, rather called for as it's a very concrete position)
   [title "1...e5"]
   [fen "B1b2rk1/p3pp1p/6p1/q1Pp4/3b1B2/2n4P/P2Q1PP1/2R1K2R b KQq - 0 1"]
  
   1...e5 (1...Qxc5 {also a good move with similar threats except the queen discovery} 2.O-O Ba6 3.Rfe1 Rxa8 4.Be3 Bxe3 5.Rxe3 d4 {easily winning: two pieces and a pawn for the rook, together with a passed pawn and dominant knight}) (1...Ba6 {The immediate Ba6 is not good enough probably but it's a fun line, the idea with Ne2+ forking bishop and knight while still taking on a8.} 2.Qxd4 Ne2+ 3.Qd2 Qxd2+ 4.Kxd2 Rxa8 5.Be3 Nxc1 6.Rxc1 {still a pawn up but it's opposite colored-bishop so always big drawing chances.}) 2.Bh6 Ba6 3.Bc6 (3.Bxd5 Rd8 4.Bf3 Bxf2+ {wins on the spot for black}) (3.Bxf8 Bxf2+ {however white recaptures loses on the spot} 4.Kxf2 Ne4+) Rc8 4.Bd7 Rxc5 5.Bg4 Bxf2+ 6.Qxf2 Ne4+ {and you're winning the house.}
  
  > **Comments:**
  > **username_0**: We protect our bishop with tempo, but then what are the following ideas?  
  > **username_1**: I've shown the main variation in the diagram. You keep the king in center, you take the trapped `a8` bishop, you have huge central space with two active minor pieces + a pawn for white's out of play rook on `h1,` so white's clearly losing. This position is not so much about ideas but concrete assessment in order to convert black's advantage, hence the diagram and discussion of side-lines.  
  > **username_2**: A sideline to add is 3.Bxf8 (by far the most natural move) which loses to the same 3...Bxf2!  
  > **username_1**: @username_2 Yes indeed, added.  
  
  ---
  
  