Answers.Body: <p><em>Very difficult</em> is relative and given enough time players of most strength should be able to find a mate in one.</p>
  
  <p>I don't have a concrete example, but in my view the following features would make it more difficult (some of these exclude each other):</p>
  
  <ul>
  <li>a large number of possible moves (i.e. lots of pieces on the board and an open position)</li>
  <li>the mating move is done by a piece moving to the back (towards the mating player)</li>
  <li>it is a non-standard mate (not one you have seen before in your tactics excercise, but rather of a studies type)</li>
  <li>the mating move is a move where the moving piece uncovers a piece that helps in the check mate (either by taking away squares from the king, or more tricky by pinning a possible defender)</li>
  <li>lots of pins are involved that prevent defenders from defending</li>
  <li>there are tempting moves that don't work for not-too-obvious reasons</li>
  <li>the move is an en passant capture or an underpromotion or castling</li>
  <li>(not sure this counts) the mate requires retrograde analysis to prove that en passant capture is allowed or that castling is allowed</li>
  <li>large distances are involved, both in the move itself and in the attacking of the king (say moving a queen from h8 to a1 to check mate a king on a8 might not be that obvious)</li>
  <li>the position is such that the pawns move unexpectedly in a direction you would not expect (down, left, right)</li>
  <li>asking for a <em>mate in one</em>  for black (without specifying that it is black's move) This can be particularly tricky if it looks as if white could mate as well.</li>
  </ul>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-03-24T17:20:36.910Z
Answers.LastActivityDate: 2020-03-24T17:35:31.567Z
Answers.LastEditDate: 2020-03-24T17:35:31.567Z
Answers.UserDisplayName: user1583209
Body: <p>Usually one-move checkmate puzzles are easy. However, I am wondering if there is a relatively more difficult one-move checkmate puzzle. Here are a few thoughts:</p>
  
  <ol>
  <li>There are many legal moves. </li>
  <li>One or several legal moves are tempting but incorrect. Especially under time pressure, an inexperienced player tends to choose such a "wrong" move.</li>
  <li>Finding the checkmate move requires some out-of-the-box thinking. It is a move that most players will not normally consider, expecially under time pressure.</li>
  </ol>
  
  <p>Anyone knows a good "difficult" one-move chekmate problem?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2020-03-25T06:12:31.033Z
Comments.Text: As it happens, I recently ran a mate-in-one competition, where even titled players struggled a little and gave many illegal moves under time pressure. You can find the problems here: https://lichess.org/study/6zUr5NJY
Comments.UserDisplayName: Remellion
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2020-03-25T07:35:08.937Z
Comments.Text: @Remellion: Thanks. I didn't know that mate in one could be that hard.
Comments.UserDisplayName: user1583209
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2020-03-25T15:33:11.373Z
Comments.Text: @Remellion, these questions are exactly the ones that I am looking for! These questions are quite non-trivial to me.
Comments.UserDisplayName: Zuriel
Tags: <checkmate><problems>
Title: What is an example of a very difficult one-move checkmate?
ThreadText: # What is an example of a very difficult one-move checkmate?
  
  (Asked by: username_0 on 2020-03-24)
  
  Usually one-move checkmate puzzles are easy. However, I am wondering if there is a relatively more difficult one-move checkmate puzzle. Here are a few thoughts:
  
  1. There are many legal moves.
  2. One or several legal moves are tempting but incorrect. Especially under time pressure, an inexperienced player tends to choose such a "wrong" move.
  3. Finding the checkmate move requires some out-of-the-box thinking. It is a move that most players will not normally consider, expecially under time pressure.
  
  Anyone knows a good "difficult" one-move chekmate problem?
  
  **Tags:** checkmate, problems
  
  > **Comments:**
  > **username_1**: As it happens, I recently ran a mate-in-one competition, where even titled players struggled a little and gave many illegal moves under time pressure. You can find the problems here: https://lichess.org/study/6zUr5NJY  
  > **username_2**: @username_1: Thanks. I didn't know that mate in one could be that hard.  
  > **username_0**: @username_1, these questions are exactly the ones that I am looking for! These questions are quite non-trivial to me.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2020-03-24. Score: 3 | Accepted answer
  
  *Very difficult* is relative and given enough time players of most strength should be able to find a mate in one.
  
  I don't have a concrete example, but in my view the following features would make it more difficult (some of these exclude each other):
  
  * a large number of possible moves (i.e. lots of pieces on the board and an open position)
  * the mating move is done by a piece moving to the back (towards the mating player)
  * it is a non-standard mate (not one you have seen before in your tactics excercise, but rather of a studies type)
  * the mating move is a move where the moving piece uncovers a piece that helps in the check mate (either by taking away squares from the king, or more tricky by pinning a possible defender)
  * lots of pins are involved that prevent defenders from defending
  * there are tempting moves that don't work for not-too-obvious reasons
  * the move is an en passant capture or an underpromotion or castling
  * (not sure this counts) the mate requires retrograde analysis to prove that en passant capture is allowed or that castling is allowed
  * large distances are involved, both in the move itself and in the attacking of the king (say moving a queen from h8 to a1 to check mate a king on a8 might not be that obvious)
  * the position is such that the pawns move unexpectedly in a direction you would not expect (down, left, right)
  * asking for a *mate in one* for black (without specifying that it is black's move) This can be particularly tricky if it looks as if white could mate as well.
  
  
  ---
  
  