Answers.Body: <p>See my book <a href="http://problem64.beda.cz/silo/kotesovec_endings_on_an_nxn_chessboard_2ed_2017.pdf" rel="nofollow noreferrer">Fairy chess endings on an n x n chessboard</a> (2017), p. 345 and 414. The ending of king + two nightriders against bare king on board 8x8 is won for the stronger side and the longest win has 22 moves.
  Also the ending king + knight + nightrider against king is a general win, see page 395.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-07-14T06:53:05.060Z
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Answers.UserDisplayName: Vaclav Kotesovec
Answers.Body: <p>The <a href="https://en.wikipedia.org/wiki/Nightrider_(chess)#Examples" rel="noreferrer">Wikipedia page on the Nightrider</a> contains an example from T. R. Dawson, published in the British Chess Magazine in 1925, where a king, knight and nightrider force a mate against a lone king. I guess a similar procedure would work for two nightriders, but you have to be a little more careful to avoid stalemate.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-09-30T14:15:23.547Z
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Answers.UserDisplayName: Glorfindel
Body: <p>I just wondered: can K + 2 nightriders force a mate against bare K? (A nightrider can make an unlimited number of knight moves in any direction - it cannot change direction partway through its move.)</p>
  
Tags: <chess-variants><knight-endgame><unorthodox-pieces>
Title: Fairy chess: KNNvK
ThreadText: # Fairy chess: KNNvK
  
  (Asked by: username_0 on 2018-09-30)
  
  I just wondered: can K + 2 nightriders force a mate against bare K? (A nightrider can make an unlimited number of knight moves in any direction - it cannot change direction partway through its move.)
  
  **Tags:** chess-variants, knight-endgame, unorthodox-pieces
  
  
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  ## 2 answers
  
  ### Answer by username_2 on 2018-09-30. Score: 8 | Accepted answer
  
  The [Wikipedia page on the Nightrider](https://en.wikipedia.org/wiki/Nightrider_(chess)#Examples) contains an example from T. R. Dawson, published in the British Chess Magazine in 1925, where a king, knight and nightrider force a mate against a lone king. I guess a similar procedure would work for two nightriders, but you have to be a little more careful to avoid stalemate.
  
  
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  ### Answer by username_1 on 2020-07-14. Score: 2
  
  See my book [Fairy chess endings on an n x n chessboard](http://problem64.beda.cz/silo/kotesovec_endings_on_an_nxn_chessboard_2ed_2017.pdf) (2017), p. 345 and 414. The ending of king + two nightriders against bare king on board 8x8 is won for the stronger side and the longest win has 22 moves.
  Also the ending king + knight + nightrider against king is a general win, see page 395.
  
  
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