Answers.Body: <p>This resembles another position referred to as the "Iron Duke." Based on my knowledge of the <em>other</em> position, I'd say that Black can draw.</p>
  
  <p>The reason is that all the potential entry points (on the fourth rank) for the white king are either occupied or "covered" by Black.  There is a (blocked) White pawn on a4, b4 and d4 are covered by the Black pawn on c5, c4 is covered by the Black bishop, e4 and g4 are covered by Black pawns, and f4 and h4 have (blocked) White pawns. The Black bishop can continue to cover c4 while moving along the diagonal to protect whatever pawn White's bishop attacks (except for the one on a6, which the king can protect). </p>
  
  <p>If White tries for an exchange of Bishops on c4, the Black K "toggles" between c6 and d6, and the White king still can't break through.</p>
  
  <p>Black <em>can</em> lose by moving his c pawn or wrongly moving his bishop. But as the position now stands, White can't force a win. Neither can Black for that matter. If he moves his (passed) c pawn, he has losing chances.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-11-03T22:52:08.910Z
Answers.Text: "If White tries for an exchange of Bishops on c4" The trick I found during my analysis is that via zugzwang White can try to play Bc4 When the Black king is on a7 (if Black bishop does not move, the king has to move, and if a6 pawn is attacked - it would have to move to a7. The question is -  can Black avoid this? and if he allows Bc4, and does not exchange bishops - is he still losing?
Answers.UserDisplayName: Joe
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-11-03T22:16:24.017Z
Answers.LastActivityDate: 2012-11-06T20:55:19.160Z
Answers.LastEditDate: 2012-11-06T20:55:19.160Z
Answers.UserDisplayName: Tom Au
Answers.Body: <p>Analysis with Houdini 6.02 signal a win for White(+4.53)at d= 41/103 after more than a quarter hour of analysis. The winning method is complicated though , and White should start with 1 Bg2. Thanks. A demo (analysis included for pure curiosity in my program )with New Engine gives + 5.58 at d= 56 , which confirms the endgame is slowly winning for White.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-08-29T17:03:54.890Z
Answers.Text: thanks for verifying this, I accepted the 'long' answer, but helps to have the recent engine's confirmation.
Answers.UserDisplayName: Joe
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-04T17:51:33.743Z
Answers.LastActivityDate: 2020-07-04T18:00:26.413Z
Answers.LastEditDate: 2020-07-04T18:00:26.413Z
Answers.UserDisplayName: Stefano
Answers.Body: <p>With new analysis from user AlwaysLearningNewStuff, we can conclude this is a win for white,</p>
  
  <p>The first critical position appears after <code>1.Be2 Kb7</code>.          </p>
  
  <pre><code>      [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]
  
         1.Be2 Kb7
  </code></pre>
  
  <p>Black defends everything at the moment, but the only moves that keep the position are <code>Kb7-a7-b7</code>. A simple triangle maneuver puts black in zugzwang.</p>
  
  <pre><code>     [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]
  
         1.Be2 Kb7 2.Kd2 Ka7 3.Kc2 Kb7 4.Kc3 
  </code></pre>
  
  <p>Now black is in <em>zugzwang</em> and loses. The following lines illustrate this:</p>
  
  <pre><code>[FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]
  
  1.Be2 Kb7 2.Kd2 Ka7 3.Kc2!+- Kb7 4.Kc3 ( 4...Ka7 5.Bc4 Be8 ( 5...Bg6 6.Be6 Kb7 7.Kc4 Kc6 8.Bd5+ Kd6 9.Bb7+- Bf7+ 10.Kd3 )( 5...Bxc4 6.Kxc4 Kb7 7.Kxc5+- ) 6.Be6 Bg6 7.Kc4 Kb7 8.Kxc5+- )( 4...Bg6 5.Bf3+! Kc7 6.Kc4 Kd6 7.Bb7+- Bf7+ 8.Kd3 )( 4...Be8 5.Kc4 Kc6 6. Bf3+ Kd6 7.Bb7+- Bf7+ 8.Kd3 ) c4! 5.Kd4! ( 5.Bxc4? Bxc4 6.Kxc4 Kc6= ) 5...Kc7 ( 5...Kc6? 6.Bxc4 Bxc4 7.Kxc4+- )( 5...Kc8? 6.Bxc4+- Bxc4 7.Kxc4 Kc7 8.Kc5 ) 6.Bf3! Kc8 7.Bd1!!+- Kc7 ( 7...Kd7 8.Bc2! Be6 9.Ke5+-)( 7...Kb7? 8.Bc2! Be6 9.Ke5 Bd7 ( 8... Bg8 9.Bxf5+- ) 10.Kd5!+- ) 8.Bc2! Be6 9.Ke5 Kd7 ( 9...Bd7 10.Kd5!+- ) 10.Bd1! Bf7 11.Kxf5 Kd6 12.Kf6!+-
  </code></pre>
  
  <p>The important idea is that after <code>4...c4!</code> White uses <code>6.Bf3!</code> to restrict Black king. After <code>6...Kc8</code> White repositions Bishop on <code>c2</code> with the move <code>7.Bd1!!</code> so the decisive <em>zugzwang</em> can be achieved. After <code>12.Kf6!</code> the rest is a matter of technique.</p>
  
  <p>The analysis is kept as brief as possible in order to preserve space, since the rest of the winning moves can be easily found with an engine. </p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-20T19:02:09.903Z
Answers.Text: Since the OP did not accept your answer, would you mind if I post my solution? If you do mind, we could exchange e-mails and I could demonstrate the decisive win for White so you can update your answer with it? Best regards.
Answers.UserDisplayName: AlwaysLearningNewStuff
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-20T19:16:59.360Z
Answers.Text: @ AlwaysLearningNewStuff Go ahead and post your own solution.
Answers.UserDisplayName: Dag Oskar Madsen
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-20T22:39:15.730Z
Answers.Text: By the way, after `7.Kc4+- Kc6 8.Bc8 Bd5+ 9.Kc3` in your third diagram White has a definite win. As for `...c4` you just take it and you win by further penetrating into Black's position. Maybe it would be better **if I edited your post** instead posting my own solution. Best regards.
Answers.UserDisplayName: AlwaysLearningNewStuff
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-20T22:45:59.653Z
Answers.Text: Black might try `8...Bg2` and get a bit of counterplay.
Answers.UserDisplayName: Dag Oskar Madsen
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-22T18:37:31.060Z
Answers.Text: Instead of posting my solution, I have decided to edit your post. This way we can avoid unnecessary redundancy. **I still wait for them to accept my edits** but I strongly believe that they will accept them. Hopefully OP will accept your solution after that. Best regards.
Answers.UserDisplayName: AlwaysLearningNewStuff
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-22T19:38:07.517Z
Answers.Text: @AlwaysLearningNewStuff; It was hard to read your suggested edit because the diagrams were messed up when they were put side to side. Perhaps this should be reported as a bug.
Answers.UserDisplayName: Dag Oskar Madsen
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-25T12:06:34.157Z
Answers.Text: @AlwaysLearningNewStuff Nice analysis! I scaled back on the number of exclamation marks, hope you don't mind :)
Answers.UserDisplayName: Dag Oskar Madsen
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-25T14:05:58.627Z
Answers.Text: I did went overboard with exclamation marks:) I have asked the OP to review your answer and hopefully accept it. Best regards.
Answers.UserDisplayName: AlwaysLearningNewStuff
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2013-10-27T10:39:35.173Z
Answers.LastActivityDate: 2014-01-25T12:04:52.867Z
Answers.LastEditDate: 2014-01-25T12:04:52.867Z
Answers.UserDisplayName: Dag Oskar Madsen
Body: <p>Black here has 3 weak pawns; if any one of them falls - he will very likely lose the game as well. If he lets White king break through via c4-c5(d5) - White will also likely win. c5 pawn is a passed pawn, but is not going anywhere. Evaluations like "White is better" are not precise enough - is it possible via analysis to prove that White definitely wins? Or that Black definitely holds? Variations or plans for both sides are welcome.</p>
  
  <p>White to move:</p>
  
  <pre><code>2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 64
  </code></pre>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-01-25T14:08:57.403Z
Comments.Text: At first I wanted to submit the solution of my own, but after seeing the solution provided by member *Dag Oskar Madsen* I have decided to **edit his answer** in order to **avoid redundancy**. I ask you to review his answer due to the improved analysis I have submitted. Please consider accepting the solution **if it solves your problem.** Thank you. Best regards.
Comments.UserDisplayName: AlwaysLearningNewStuff
Tags: <analysis><endgame><bishops><bishop-endgame>
Title: Typical Good Bishop vs. Bad Bishop endgame - how to decide if stronger side has a definite win
ThreadText: # Typical Good Bishop vs. Bad Bishop endgame - how to decide if stronger side has a definite win
  
  (Asked by: username_0 on 2012-11-02)
  
  Black here has 3 weak pawns; if any one of them falls - he will very likely lose the game as well. If he lets White king break through via c4-c5(d5) - White will also likely win. c5 pawn is a passed pawn, but is not going anywhere. Evaluations like "White is better" are not precise enough - is it possible via analysis to prove that White definitely wins? Or that Black definitely holds? Variations or plans for both sides are welcome.
  
  White to move:
  
  ```
  2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 64
  
  ```
  
  **Tags:** analysis, endgame, bishops, bishop-endgame
  
  > **Comments:**
  > **username_1**: At first I wanted to submit the solution of my own, but after seeing the solution provided by member *username_4* I have decided to **edit his answer** in order to **avoid redundancy**. I ask you to review his answer due to the improved analysis I have submitted. Please consider accepting the solution **if it solves your problem.** Thank you. Best regards.  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_4 on 2013-10-27. Score: 11 | Accepted answer
  
  With new analysis from user username_1, we can conclude this is a win for white,
  
  The first critical position appears after `1.Be2 Kb7`.
  
  ```
        [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]
  
         1.Be2 Kb7
  
  ```
  
  Black defends everything at the moment, but the only moves that keep the position are `Kb7-a7-b7`. A simple triangle maneuver puts black in zugzwang.
  
  ```
       [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]
  
         1.Be2 Kb7 2.Kd2 Ka7 3.Kc2 Kb7 4.Kc3 
  
  ```
  
  Now black is in *zugzwang* and loses. The following lines illustrate this:
  
  ```
  [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]
  
  1.Be2 Kb7 2.Kd2 Ka7 3.Kc2!+- Kb7 4.Kc3 ( 4...Ka7 5.Bc4 Be8 ( 5...Bg6 6.Be6 Kb7 7.Kc4 Kc6 8.Bd5+ Kd6 9.Bb7+- Bf7+ 10.Kd3 )( 5...Bxc4 6.Kxc4 Kb7 7.Kxc5+- ) 6.Be6 Bg6 7.Kc4 Kb7 8.Kxc5+- )( 4...Bg6 5.Bf3+! Kc7 6.Kc4 Kd6 7.Bb7+- Bf7+ 8.Kd3 )( 4...Be8 5.Kc4 Kc6 6. Bf3+ Kd6 7.Bb7+- Bf7+ 8.Kd3 ) c4! 5.Kd4! ( 5.Bxc4? Bxc4 6.Kxc4 Kc6= ) 5...Kc7 ( 5...Kc6? 6.Bxc4 Bxc4 7.Kxc4+- )( 5...Kc8? 6.Bxc4+- Bxc4 7.Kxc4 Kc7 8.Kc5 ) 6.Bf3! Kc8 7.Bd1!!+- Kc7 ( 7...Kd7 8.Bc2! Be6 9.Ke5+-)( 7...Kb7? 8.Bc2! Be6 9.Ke5 Bd7 ( 8... Bg8 9.Bxf5+- ) 10.Kd5!+- ) 8.Bc2! Be6 9.Ke5 Kd7 ( 9...Bd7 10.Kd5!+- ) 10.Bd1! Bf7 11.Kxf5 Kd6 12.Kf6!+-
  
  ```
  
  The important idea is that after `4...c4!` White uses `6.Bf3!` to restrict Black king. After `6...Kc8` White repositions Bishop on `c2` with the move `7.Bd1!!` so the decisive *zugzwang* can be achieved. After `12.Kf6!` the rest is a matter of technique.
  
  The analysis is kept as brief as possible in order to preserve space, since the rest of the winning moves can be easily found with an engine.
  
  > **Comments:**
  > **username_1**: Since the OP did not accept your answer, would you mind if I post my solution? If you do mind, we could exchange e-mails and I could demonstrate the decisive win for White so you can update your answer with it? Best regards.  
  > **username_4**: @ username_1 Go ahead and post your own solution.  
  > **username_1**: By the way, after `7.Kc4+- Kc6 8.Bc8 Bd5+ 9.Kc3` in your third diagram White has a definite win. As for `...c4` you just take it and you win by further penetrating into Black's position. Maybe it would be better **if I edited your post** instead posting my own solution. Best regards.  
  > **username_4**: Black might try `8...Bg2` and get a bit of counterplay.  
  > **username_1**: Instead of posting my solution, I have decided to edit your post. This way we can avoid unnecessary redundancy. **I still wait for them to accept my edits** but I strongly believe that they will accept them. Hopefully OP will accept your solution after that. Best regards.  
  > **username_4**: @username_1; It was hard to read your suggested edit because the diagrams were messed up when they were put side to side. Perhaps this should be reported as a bug.  
  > **username_4**: @username_1 Nice analysis! I scaled back on the number of exclamation marks, hope you don't mind :)  
  > **username_1**: I did went overboard with exclamation marks:) I have asked the OP to review your answer and hopefully accept it. Best regards.  
  
  ---
  
  ### Answer by username_2 on 2012-11-03. Score: 2
  
  This resembles another position referred to as the "Iron Duke." Based on my knowledge of the *other* position, I'd say that Black can draw.
  
  The reason is that all the potential entry points (on the fourth rank) for the white king are either occupied or "covered" by Black. There is a (blocked) White pawn on a4, b4 and d4 are covered by the Black pawn on c5, c4 is covered by the Black bishop, e4 and g4 are covered by Black pawns, and f4 and h4 have (blocked) White pawns. The Black bishop can continue to cover c4 while moving along the diagonal to protect whatever pawn White's bishop attacks (except for the one on a6, which the king can protect).
  
  If White tries for an exchange of Bishops on c4, the Black K "toggles" between c6 and d6, and the White king still can't break through.
  
  Black *can* lose by moving his c pawn or wrongly moving his bishop. But as the position now stands, White can't force a win. Neither can Black for that matter. If he moves his (passed) c pawn, he has losing chances.
  
  > **Comments:**
  > **username_0**: "If White tries for an exchange of Bishops on c4" The trick I found during my analysis is that via zugzwang White can try to play Bc4 When the Black king is on a7 (if Black bishop does not move, the king has to move, and if a6 pawn is attacked - it would have to move to a7. The question is -  can Black avoid this? and if he allows Bc4, and does not exchange bishops - is he still losing?  
  
  ---
  
  ### Answer by username_3 on 2020-07-04. Score: 1
  
  Analysis with Houdini 6.02 signal a win for White(+4.53)at d= 41/103 after more than a quarter hour of analysis. The winning method is complicated though , and White should start with 1 Bg2. Thanks. A demo (analysis included for pure curiosity in my program )with New Engine gives + 5.58 at d= 56 , which confirms the endgame is slowly winning for White.
  
  > **Comments:**
  > **username_0**: thanks for verifying this, I accepted the 'long' answer, but helps to have the recent engine's confirmation.  
  
  ---
  
  