Answers.Body: <blockquote>
    <p>At one time, it was believed that all winnable endgames could be won
    within fifty moves. However, in the early twentieth century, some
    exceptions were found, including A. A. Troitsky's (1866-1942) analysis
    of the two knights endgame as well as the endgame of a rook and bishop
    versus a rook. The rules of chess were revised several times to admit
    exceptions to the fifty-move rule for certain specific situations.
    Early on, the fifty-move rule applied to tournament games but not to
    match games (Troitzky 2006:197).</p>
  </blockquote>
  
  <p>SOURCE: <a href="http://en.wikipedia.org/wiki/Fifty-move_rule">Fifty-move rule</a></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-03-24T22:41:55.683Z
Answers.Text: @Daniel  I guess those extremely long endgames include captures (which are relevant for the 50 move rule), don't they?
Answers.UserDisplayName: user1583209
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-11-01T13:07:46.907Z
Answers.Text: @user1583209 No!  It's 517 moves to get to a capture (which creates a "quickly" winnable end-game. (And the in the particular case, there are no pawns).
Answers.UserDisplayName: Martin Bonner supports Monica
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-08-23T15:35:00.670Z
Answers.Text: Most unfortunate. The last of the fundamental mate patterns (two knights vs pawn) takes 115 moves.
Answers.UserDisplayName: Joshua
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-05-03T19:47:01.420Z
Answers.Text: This is interesting.  There are some complex endgames that can not in fact be won in fifty moves - for example, multiple pieces vs. queen - but that can be won.
Answers.UserDisplayName: Andrew Latham
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-05-03T20:39:48.577Z
Answers.Text: @Andrew Latham: This [table of "pawnless endgames"](http://en.wikipedia.org/wiki/Pawnless_chess_endgame#Tables), under the "longest win" column, provides additional examples too; note that Stiller and Nunn both say 243 is the longest.
Answers.UserDisplayName: blunders
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-05-04T02:36:29.493Z
Answers.Text: @Blunders: see my comment to Andrew's answer [here](http://chess.stackexchange.com/a/131/86): there's a setup in which it takes White 517 moves to force a winning endgame - not even mate!
Answers.UserDisplayName: Daniel
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2012-05-03T12:33:34.037Z
Answers.LastActivityDate: 2012-05-03T12:33:34.037Z
Answers.UserDisplayName: blunders
Body: <p>The reason for the 50-move rule, along with the triple-repetition rule is to make chess definitely finite. How did one arrive at the number 50? What would change if it was 40 or 60? Is the number 50 chosen carefully?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2012-06-10T16:15:05.623Z
Comments.Text: I've never seen the 50 move rule actually invoked, since maybe 6th grade.
Comments.UserDisplayName: Tony Ennis
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2012-07-06T21:35:27.927Z
Comments.Text: @TonyEnnis, that's because you haven't seen [this](http://www.chessgames.com/perl/chessgame?gid=1497429) (utterly absurd) game.  (Actually, the 50-move rule isn't invoked in this game, but Nakamura tricks the computer into making errors when it tries to avoid the 50-move rule.)
Comments.UserDisplayName: Kyralessa
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2012-07-06T21:49:17.317Z
Comments.Text: @Kyralessa: Wow! Just... WOW
Comments.UserDisplayName: Armen Tsirunyan
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2012-07-06T23:54:16.740Z
Comments.Text: Don't make the mistake of showing that game to your seven-year-old, like I did.  Apparently he decided that if that tedious back-and-forth stuff was good enough for Nakamura, it was good enough for him as well.
Comments.UserDisplayName: Kyralessa
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2012-07-07T01:20:47.307Z
Comments.Text: @kyralessa that game is cool.  You can see Nakamura figuring out how the computer is working, and then using this as a weapon.
Comments.UserDisplayName: Tony Ennis
Tags: <history><50-move-rule>
Title: Why was 50 chosen for the 50-move rule?
ThreadText: # Why was 50 chosen for the 50-move rule?
  
  (Asked by: username_0 on 2012-05-03)
  
  The reason for the 50-move rule, along with the triple-repetition rule is to make chess definitely finite. How did one arrive at the number 50? What would change if it was 40 or 60? Is the number 50 chosen carefully?
  
  **Tags:** history, 50-move-rule
  
  > **Comments:**
  > **username_1**: I've never seen the 50 move rule actually invoked, since maybe 6th grade.  
  > **username_2**: @username_1, that's because you haven't seen [this](http://www.chessgames.com/perl/chessgame?gid=1497429) (utterly absurd) game.  (Actually, the 50-move rule isn't invoked in this game, but Nakamura tricks the computer into making errors when it tries to avoid the 50-move rule.)  
  > **username_0**: @username_2: Wow! Just... WOW  
  > **username_2**: Don't make the mistake of showing that game to your seven-year-old, like I did.  Apparently he decided that if that tedious back-and-forth stuff was good enough for Nakamura, it was good enough for him as well.  
  > **username_1**: @username_2 that game is cool.  You can see Nakamura figuring out how the computer is working, and then using this as a weapon.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_3 on 2012-05-03. Score: 17 | Accepted answer
  
  > At one time, it was believed that all winnable endgames could be won
  > within fifty moves. However, in the early twentieth century, some
  > exceptions were found, including A. A. Troitsky's (1866-1942) analysis
  > of the two knights endgame as well as the endgame of a rook and bishop
  > versus a rook. The rules of chess were revised several times to admit
  > exceptions to the fifty-move rule for certain specific situations.
  > Early on, the fifty-move rule applied to tournament games but not to
  > match games (Troitzky 2006:197).
  
  SOURCE: [Fifty-move rule](http://en.wikipedia.org/wiki/Fifty-move_rule)
  
  > **Comments:**
  > **username_7**: This is interesting.  There are some complex endgames that can not in fact be won in fifty moves - for example, multiple pieces vs. queen - but that can be won.  
  > **username_3**: @username_7: This [table of "pawnless endgames"](http://en.wikipedia.org/wiki/Pawnless_chess_endgame#Tables), under the "longest win" column, provides additional examples too; note that Stiller and Nunn both say 243 is the longest.  
  > **username_8**: @username_3: see my comment to username_7's answer [here](http://chess.stackexchange.com/a/131/86): there's a setup in which it takes White 517 moves to force a winning endgame - not even mate!  
  > **username_4**: @username_8  I guess those extremely long endgames include captures (which are relevant for the 50 move rule), don't they?  
  > **username_5**: @username_4 No!  It's 517 moves to get to a capture (which creates a "quickly" winnable end-game. (And the in the particular case, there are no pawns).  
  > **username_6**: Most unfortunate. The last of the fundamental mate patterns (two knights vs pawn) takes 115 moves.  
  
  ---
  
  