Answers.Body: <p>First, you have to understand that computers sometimes play non-human moves because they see things that humans most times do not. It probably sees threats to the white king based on the black bishop pair.</p>
  
  <p>In this position, white is just lost, and those bishops on d5 and c5 working together are incredibly strong, so trading off one of them is desirable. What makes it a little strange is that it gives black connected passed pawns, but they are hard to maintain, let alone advance, due to the active white rooks, and unfortunate black Ra8, but it still does not change the outcome.</p>
  
  <p>Also, the Ra8 is not lost to Nd5 cd; Rg8 Bf8; Rf1 Ke7, but it does tie black up some, which is another reason that Nd5 was best. It is hard to finish his development.</p>
  
  <pre><code> [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  
   1. Nxd5 cxd5 2. Rg8+ Bf8 3. Rf1 Ke7 4. Rf5 {with a little counterplay that requires accuracy from black} Rf6! 5. Rxh5 (5. Rxe5? Kf7 6. Rh8 Bd6 7. Rxa8 Bxe5+ 8. Kg2 Bxb2 9. Rxa7 Kg6-+)  Rc8! 6. Rxe5 Kd7!! 7. Rd5 Bd6+ 8. Rxd6+ Rxd6 9. Rg7 Kc6 10. Rxa7 Kb6 {with an easy win from here}  
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-10T23:43:16.630Z
Answers.Text: I would have made that move.  And I am human.  The two bishops are too powerful to allow to remain.
Answers.UserDisplayName: yobamamama
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-07T21:50:10.250Z
Answers.LastActivityDate: 2019-12-07T22:18:57.417Z
Answers.LastEditDate: 2019-12-07T22:18:57.417Z
Answers.UserDisplayName: PhishMaster
Answers.Body: <p>(Disclaimer: this is basically a (hopefully) developed form of yobamamama's answer with some opinions of my own thorwn in. The latter is the reason why I decided to write this up an independent answer. Feel free to edit or combine with yobamamama's answer)</p>
  
  <p>First, I think the move is reported as best <em>not for its merit; but it might be actually forced</em>. Black is threatening 1.__ h4+ 2.Kg4 Be6+ 3.Kg5 (3.Kf3 Bxh3) 4.Be3+. To stop this threat, other than 1.Nxd5, white has following options (may not be exhaustive)<br>
  a) 1.Ng1 (this retreat looks like  a very reasonable move here)<br>
  b) 1.Re1 (this look a kicking back move; may not work)<br>
  c) 1.Ng5 (risky)<br>
  [The move 1.Rf1 is not good enough. Black can play 1.__ h4+ 2.Kg4 Be6+ 3.Kg5 Be3+ 4.~f4 Rh8]<br>
  [I think 1.Ng5 is risky due to 1.__ Kf8; i am not sure about this]  </p>
  
  <p><strong>Coming back to the move 1.Nxd5 cxd5</strong>.
  Now, 2.Rf1 seems to be superior to outright 2.Rg8+ suggested by Phishmaster(at least when you play against a human player). Note that 2.Rf1 threatens 3.Rg8+. This ties up black's options for a practical game (still, options 3.Rh8 and 3.Rd8 look good for black).</p>
  
  <pre><code> [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  
  1. Nxd5 cxd5 2. Rf1
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T21:26:25.380Z
Answers.Text: I commented on this very position, Rf1 is not superior to Rg8. It is an easy and SIMPLE loss after just 0-0-0, and I went into detail in my back-and-forth with yobamamama. The problem is that doubling on the 7th here brings has no threat, and does nothing to contain the passed pawns. The move Rg8, while still losing, at least is serious counterplay, requiring precision by black. In other words, Rf1 easy win, Rg8 not so easy.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-09T08:21:32.247Z
Answers.Text: Why are you so sure black can castle? Nobody mentioned that the black king never moved!
Answers.UserDisplayName: Cyriac Antony
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-01-17T02:41:08.610Z
Answers.Text: What the difference between best on its merits, versus being forced?
Answers.UserDisplayName: Acccumulation
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T16:40:46.327Z
Answers.LastActivityDate: 2019-12-08T16:40:46.327Z
Answers.UserDisplayName: Cyriac Antony
Answers.Body: <p>After the recapture white moves his rook to f1 and then next move to the seventh rank (f7).</p>
  
  <pre><code> [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  
  1. Nxd5 cxd5 2. Rf1 null 3. Rff7
  </code></pre>
  
  <p>Note that by 2.Rf1, white threatens 3.Rg8+. Also, this brings the other rook into play. The game may be still lost, but this probably gives better fighting chances.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-07T23:13:05.360Z
Answers.Text: -1. The 7th is easily covered there after Rf1? by just 0-0-0 Rff7 and then any number of moves defends. The computer likes Rc6, but the even the natural Bb6 evals at -3.75. Then the pawns roll, and are incredibly dangerous.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T03:04:04.747Z
Answers.Text: @PhishMaster  -  I did not use a computer.  But surmised what would happen after nxb  .Else why give black connected passed pawns.
Answers.UserDisplayName: yobamamama
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T03:05:30.070Z
Answers.Text: Read my comment above. I explained it all in detail using a computer and 30+ years of experience as a Master, and you can play it out on the PGN board I inserted.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T04:27:39.433Z
Answers.Text: @PhishMaster -- Whatever.  White is in a bad way.  What does white do after pxn?  The two bishops are very strong.  But the connected pawns now makes up for losing one of them.  White should lose no matter what.
Answers.UserDisplayName: yobamamama
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T09:25:38.453Z
Answers.Text: Whatever? Did you bother to read the analysis, and WHY black cannot easily push them? Just because something is optically good, like your rooks on the 7th, you must take into account the specifics of the position. You are refusing to look at white's pluses in the position, and that is the awkward placing of black's pieces, which matter more than pawns you do not have time to push.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T10:14:36.473Z
Answers.Text: And I never said while was not lost, but Nxd5 still makes it the most challenging. P.S. Yes, black has passers, but they are weak due to black's bad B and Ra8 in the line I gave, and that the white rooks are so active: Either the Bf8 falls, or one of the pawns. In addition, should you leave the B-pair, the Bd5 moves to c4, and the one remaining pawn runs like the wind. Specifics count.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T13:49:53.280Z
Answers.Text: @PhishMaster  --  My analysis says white is lost.  I see the problems but those pawns will dominate.  the rooks on the 7th are a threat but that can be easily defended.
Answers.UserDisplayName: yobamamama
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T13:59:50.787Z
Answers.Text: Your "analysis" is a series of shallow generalizations that a 3600+ computer does not agree with. Sorry, you can argue all you want, but that is not going to change.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-08T14:57:56.613Z
Answers.Text: @PhishMaster  -  I am not arguing.  Don't care if you change.  I would prefer to play black in that position.  At least against a real person.  I would not waste time playing a computer.
Answers.UserDisplayName: yobamamama
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-10T23:18:12.387Z
Answers.Text: I don't know for sure that you are the one, who down-voted three of my posts in succession today (it was clearly some kind of payback from someone), but despite all the down-votes you have received since you have been here, this was the ONLY one I gave to you. I have only issued 5 down-votes total to all users, ever. I have not been a fan of your posts, but I am still very hesitant to down-vote at all, but it is not me, who is down-voting you.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-10T23:19:27.737Z
Answers.Text: P.S. I even up-voted your comment today about English and the use of pronouns.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-11T14:44:42.993Z
Answers.Text: @Rewan, that is great too. I like full be careful.
Answers.UserDisplayName: PhishMaster
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-12-07T22:13:57.680Z
Answers.LastActivityDate: 2019-12-08T17:52:59.773Z
Answers.LastEditDate: 2019-12-08T17:52:59.773Z
Answers.UserDisplayName: yobamamama
Body: <p>I'm new to chess. In the position below, lichess analysis says that Nxd5 is the best move for white. But can't black just capture the knight afterwards with his pawn and threaten white's pawn and rook in the top right hand corner after white's knight is dead? What makes Nxd5 the best move here?</p>
  
  <pre><code> [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  </code></pre>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-07T21:42:26.843Z
Comments.Text: Without the bishop on d5 what threats does white have? How can he/she force Black to make moves that leave black rather tied down? And BTW in English the Tower is called a "Rook" - English being as logical as it it usually is.
Comments.UserDisplayName: Ian Bush
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-07T21:45:38.110Z
Comments.Text: Also can Black still castle Queen Side? (Hint!)
Comments.UserDisplayName: Ian Bush
Tags: <analysis><endgame>
Title: Why is white's best play Nxd5 here?
ThreadText: # Why is white's best play Nxd5 here?
  
  (Asked by: username_0 on 2019-12-07)
  
  I'm new to chess. In the position below, lichess analysis says that Nxd5 is the best move for white. But can't black just capture the knight afterwards with his pawn and threaten white's pawn and rook in the top right hand corner after white's knight is dead? What makes Nxd5 the best move here?
  
  ```
   [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  
  ```
  
  **Tags:** analysis, endgame
  
  > **Comments:**
  > **username_1**: Without the bishop on d5 what threats does white have? How can he/she force Black to make moves that leave black rather tied down? And BTW in English the Tower is called a "Rook" - English being as logical as it it usually is.  
  > **username_1**: Also can Black still castle Queen Side? (Hint!)  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_2 on 2019-12-07. Score: 3
  
  First, you have to understand that computers sometimes play non-human moves because they see things that humans most times do not. It probably sees threats to the white king based on the black bishop pair.
  
  In this position, white is just lost, and those bishops on d5 and c5 working together are incredibly strong, so trading off one of them is desirable. What makes it a little strange is that it gives black connected passed pawns, but they are hard to maintain, let alone advance, due to the active white rooks, and unfortunate black Ra8, but it still does not change the outcome.
  
  Also, the Ra8 is not lost to Nd5 cd; Rg8 Bf8; Rf1 Ke7, but it does tie black up some, which is another reason that Nd5 was best. It is hard to finish his development.
  
  ```
   [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  
   1. Nxd5 cxd5 2. Rg8+ Bf8 3. Rf1 Ke7 4. Rf5 {with a little counterplay that requires accuracy from black} Rf6! 5. Rxh5 (5. Rxe5? Kf7 6. Rh8 Bd6 7. Rxa8 Bxe5+ 8. Kg2 Bxb2 9. Rxa7 Kg6-+)  Rc8! 6. Rxe5 Kd7!! 7. Rd5 Bd6+ 8. Rxd6+ Rxd6 9. Rg7 Kc6 10. Rxa7 Kb6 {with an easy win from here}  
  
  ```
  
  > **Comments:**
  > **username_3**: I would have made that move.  And I am human.  The two bishops are too powerful to allow to remain.  
  
  ---
  
  ### Answer by username_4 on 2019-12-08. Score: 0
  
  (Disclaimer: this is basically a (hopefully) developed form of username_3's answer with some opinions of my own thorwn in. The latter is the reason why I decided to write this up an independent answer. Feel free to edit or combine with username_3's answer)
  
  First, I think the move is reported as best *not for its merit; but it might be actually forced*. Black is threatening 1.\_\_ h4+ 2.Kg4 Be6+ 3.Kg5 (3.Kf3 Bxh3) 4.Be3+. To stop this threat, other than 1.Nxd5, white has following options (may not be exhaustive)  
  a) 1.Ng1 (this retreat looks like a very reasonable move here)  
  b) 1.Re1 (this look a kicking back move; may not work)  
  c) 1.Ng5 (risky)  
  [The move 1.Rf1 is not good enough. Black can play 1.\_\_ h4+ 2.Kg4 Be6+ 3.Kg5 Be3+ 4.~f4 Rh8]  
  [I think 1.Ng5 is risky due to 1.\_\_ Kf8; i am not sure about this]
  
  **Coming back to the move 1.Nxd5 cxd5**.
  Now, 2.Rf1 seems to be superior to outright 2.Rg8+ suggested by username_2(at least when you play against a human player). Note that 2.Rf1 threatens 3.Rg8+. This ties up black's options for a practical game (still, options 3.Rh8 and 3.Rd8 look good for black).
  
  ```
   [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  
  1. Nxd5 cxd5 2. Rf1
  
  ```
  
  > **Comments:**
  > **username_2**: I commented on this very position, Rf1 is not superior to Rg8. It is an easy and SIMPLE loss after just 0-0-0, and I went into detail in my back-and-forth with username_3. The problem is that doubling on the 7th here brings has no threat, and does nothing to contain the passed pawns. The move Rg8, while still losing, at least is serious counterplay, requiring precision by black. In other words, Rf1 easy win, Rg8 not so easy.  
  > **username_4**: Why are you so sure black can castle? Nobody mentioned that the black king never moved!  
  > **username_5**: What the difference between best on its merits, versus being forced?  
  
  ---
  
  ### Answer by username_3 on 2019-12-07. Score: 0
  
  After the recapture white moves his rook to f1 and then next move to the seventh rank (f7).
  
  ```
   [FEN "r3k3/p5R1/p1p4r/2bbp2p/8/P1N3KN/1P5P/R7 w q - 0 1"]
  
  1. Nxd5 cxd5 2. Rf1 null 3. Rff7
  
  ```
  
  Note that by 2.Rf1, white threatens 3.Rg8+. Also, this brings the other rook into play. The game may be still lost, but this probably gives better fighting chances.
  
  > **Comments:**
  > **username_2**: -1. The 7th is easily covered there after Rf1? by just 0-0-0 Rff7 and then any number of moves defends. The computer likes Rc6, but the even the natural Bb6 evals at -3.75. Then the pawns roll, and are incredibly dangerous.  
  > **username_3**: @username_2  -  I did not use a computer.  But surmised what would happen after nxb  .Else why give black connected passed pawns.  
  > **username_2**: Read my comment above. I explained it all in detail using a computer and 30+ years of experience as a Master, and you can play it out on the PGN board I inserted.  
  > **username_3**: @username_2 -- Whatever.  White is in a bad way.  What does white do after pxn?  The two bishops are very strong.  But the connected pawns now makes up for losing one of them.  White should lose no matter what.  
  > **username_2**: Whatever? Did you bother to read the analysis, and WHY black cannot easily push them? Just because something is optically good, like your rooks on the 7th, you must take into account the specifics of the position. You are refusing to look at white's pluses in the position, and that is the awkward placing of black's pieces, which matter more than pawns you do not have time to push.  
  > **username_2**: And I never said while was not lost, but Nxd5 still makes it the most challenging. P.S. Yes, black has passers, but they are weak due to black's bad B and Ra8 in the line I gave, and that the white rooks are so active: Either the Bf8 falls, or one of the pawns. In addition, should you leave the B-pair, the Bd5 moves to c4, and the one remaining pawn runs like the wind. Specifics count.  
  > **username_3**: @username_2  --  My analysis says white is lost.  I see the problems but those pawns will dominate.  the rooks on the 7th are a threat but that can be easily defended.  
  > **username_2**: Your "analysis" is a series of shallow generalizations that a 3600+ computer does not agree with. Sorry, you can argue all you want, but that is not going to change.  
  > **username_3**: @username_2  -  I am not arguing.  Don't care if you change.  I would prefer to play black in that position.  At least against a real person.  I would not waste time playing a computer.  
  > **username_2**: I don't know for sure that you are the one, who down-voted three of my posts in succession today (it was clearly some kind of payback from someone), but despite all the down-votes you have received since you have been here, this was the ONLY one I gave to you. I have only issued 5 down-votes total to all users, ever. I have not been a fan of your posts, but I am still very hesitant to down-vote at all, but it is not me, who is down-voting you.  
  > **username_2**: P.S. I even up-voted your comment today about English and the use of pronouns.  
  > **username_2**: @Rewan, that is great too. I like full be careful.  
  
  ---
  
  