Answers.Body: <blockquote>
    <p>What would make you play Nc7? </p>
  </blockquote>
  
  <p>It is the <strong>only</strong> move with which White can give check mate <strong>in two</strong> moves.</p>
  
  <blockquote>
    <p>This results in checkmate in 2 if, as the computer does, Rxe5 is played, but why wouldn't the computer just play Nxg5, winning the queen and preventing checkmate? </p>
  </blockquote>
  
  <p>On <code>1. ...Nxg5</code> White plays <code>2.Rd5</code> which check mates.</p>
  
  <blockquote>
    <p>Or d1 and promote to a queen? </p>
  </blockquote>
  
  <p>On <code>1. ...d1Q</code> White plays <code>2.Rd5</code> which check mates.</p>
  
  <h2>SUMMARY:</h2>
  
  <p>1.<code>Nc7</code> has been played to free the rook on <code>e5</code> to give check mate, by coming to <code>d5</code>.</p>
  
  <p>This is why computer played <code>1. ...Rxe5</code>, since on every Black's move <code>2.Rd5</code> check mates, except for these:</p>
  
  <p><code>1. ...Ne3</code> but then White mates with <code>2.Rxe4</code>.</p>
  
  <p><code>1. ...Nxe5</code> where White mates with <code>2.Rxd6</code>.</p>
  
  <p><code>1. ...Bxe5</code> where White mates with <code>2.Qxd2</code>.</p>
  
  <p><code>1. ...dxe5</code> where White mates with <code>2.Bc5</code>.</p>
  
  <p><code>1. ...Kxe5</code> where White mates with <code>2.Bg7</code>.</p>
  
  <p>Best regards.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-03-04T10:33:36.873Z
Answers.Text: You forgot the most important thing ;-), i.e. that this is a chess problem, which simply has different rules than an OTB game (for this example, the problem asks not for any win, but for the unique 2#). This usually confuses the novice.
Answers.UserDisplayName: Hauke Reddmann
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-01-05T10:12:06.277Z
Answers.LastActivityDate: 2014-01-19T23:52:20.143Z
Answers.LastEditDate: 2014-01-19T23:52:20.143Z
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Body: <pre><code>[FEN &quot;5B2/3p1n2/R2p4/1P1NRBQ1/1KPkrb2/1p6/2Pp1Pn1/4r3 w - - 0 1&quot;]
  
  1. Nc7! Rxe5 (1... Nxg5) (1... d1=Q) 2.c3#
  </code></pre>
  <p>What would make you play Nc7? This results in checkmate in 2 if, as the computer does, Rxe5 is played. But why wouldn't the computer just play Nxg5, winning the queen and preventing checkmate? Or why not play to d1 and promote to a queen?</p>
  
Tags: <analysis><problems>
Title: A chess problem question: Why is this the solution?
ThreadText: # A chess problem question: Why is this the solution?
  
  (Asked by: username_0 on 2014-01-05)
  
  [FEN "5B2/3p1n2/R2p4/1P1NRBQ1/1KPkrb2/1p6/2Pp1Pn1/4r3 w - - 0 1"]
  
  1. Nc7! Rxe5 (1... Nxg5) (1... d1=Q) 2.c3#
  
  What would make you play Nc7? This results in checkmate in 2 if, as the computer does, Rxe5 is played. But why wouldn't the computer just play Nxg5, winning the queen and preventing checkmate? Or why not play to d1 and promote to a queen?
  
  **Tags:** analysis, problems
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2014-01-05. Score: 12 | Accepted answer
  
  > What would make you play Nc7?
  
  It is the **only** move with which White can give check mate **in two** moves.
  
  > This results in checkmate in 2 if, as the computer does, Rxe5 is played, but why wouldn't the computer just play Nxg5, winning the queen and preventing checkmate?
  
  On `1. ...Nxg5` White plays `2.Rd5` which check mates.
  
  > Or d1 and promote to a queen?
  
  On `1. ...d1Q` White plays `2.Rd5` which check mates.
  
  ## SUMMARY:
  
  1.`Nc7` has been played to free the rook on `e5` to give check mate, by coming to `d5`.
  
  This is why computer played `1. ...Rxe5`, since on every Black's move `2.Rd5` check mates, except for these:
  
  `1. ...Ne3` but then White mates with `2.Rxe4`.
  
  `1. ...Nxe5` where White mates with `2.Rxd6`.
  
  `1. ...Bxe5` where White mates with `2.Qxd2`.
  
  `1. ...dxe5` where White mates with `2.Bc5`.
  
  `1. ...Kxe5` where White mates with `2.Bg7`.
  
  Best regards.
  
  > **Comments:**
  > **username_2**: You forgot the most important thing ;-), i.e. that this is a chess problem, which simply has different rules than an OTB game (for this example, the problem asks not for any win, but for the unique 2#). This usually confuses the novice.  
  
  ---
  
  