Answers.Body: <p>According to wikipedia <a href="http://en.wikipedia.org/wiki/Pawnless_chess_endgame" rel="nofollow noreferrer">http://en.wikipedia.org/wiki/Pawnless_chess_endgame</a>, section "Endgames requiring more than 100 moves to win", the longest is</p>
  
  <p>R+N vs N+N = 243 moves
  with 78% of winning chances.</p>
  
  <p>R+B vs N+N = 223 moves
  with 96% of winning chances.</p>
  
  <p>R+N vs B+N = 190 moves
  with 72% winning chances.</p>
  
  <p>and the list goes on...</p>
  
  <p>Another way is looking at the database of mutual zugzwangs at <a href="http://chess.jaet.org/cgi-bin/mzugs?sort=wmaxdtm" rel="nofollow noreferrer">http://chess.jaet.org/cgi-bin/mzugs?sort=wmaxdtm</a> sorted by maxdtm (depth to conversion or mate).</p>
  
  <p>John Nunn's book "Secrets of pawnless endgames" (I love that book) in the 2nd editions expands coverage to some of the endings mentioned (although very briefly).</p>
  
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Answers.CreationDate: 2015-01-12T00:21:05.660Z
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Answers.LastEditDate: 2017-08-09T05:08:35.507Z
Answers.UserDisplayName: Fernando Gonzalez Sanchez
Answers.Body: <p>If you mean "hardest" == "longest": There are 7-man table bases available and it is said that the longest pawnless ending takes 549 moves. It is KQB vs. KRBN.</p>
  
  <p>Resources: <a href="http://tb7.chessok.com/articles/Top8DTM_eng" rel="nofollow noreferrer">http://tb7.chessok.com/articles/Top8DTM_eng</a></p>
  
  <p>And in case you are too lazy to go through the moves by yourself :-): <a href="http://tb7.chessok.com/probe/745/61" rel="nofollow noreferrer">http://tb7.chessok.com/probe/745/61</a></p>
  
  <p>I think that is what is known today. I would not be surprised if even longer pawnless endings exists with 8 pieces on the board.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-01-15T14:38:25.080Z
Answers.Text: Do you know what the winning chances are in this endgame if it was a random position?
Answers.UserDisplayName: user5649
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Answers.Text: No, I don't have any other information on the winning chances for this endgame.
Answers.UserDisplayName: Jagu
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Answers.Text: ah, cuz that's what i kinda wanted to know, it had to be at least 90% winning chance
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Answers.UserDisplayName: Jagu
Body: <p>I know two pawnless endgames that go over the 50-move rule.</p>
  
  <p>King and 2 Bishops vs. King and Knight = 70 moves average.</p>
  
  <p>King, Rook and Bishop vs. King and 2 Knights = 200 move average.</p>
  
  <p>What others are there?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-01-12T00:21:49.970Z
Comments.Text: I feel the FIDE should reform the 50 move law & apply exceptions to these cases (would be epic a championship game decided in one of those endings!)
Comments.UserDisplayName: Fernando Gonzalez Sanchez
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Comments.CreationDate: 2015-01-12T22:04:03.633Z
Comments.Text: @FernandoGonzalezSanchez They did, for a while. It made very little difference, since these endgames come up very rarely in real life. So they moved back to a uniform 50 moves.
Comments.UserDisplayName: David Richerby
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-01-19T02:40:15.163Z
Comments.Text: Good to know, btw a similar question: http://chess.stackexchange.com/questions/351/what-is-the-status-for-seven-man-end-game-table-bases
Comments.UserDisplayName: Fernando Gonzalez Sanchez
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-01-20T16:42:35.943Z
Comments.Text: @FernandoGonzalezSanchez not the same :l
Comments.UserDisplayName: user5649
Tags: <endgame><50-move-rule>
Title: What are the hardest pawnless endgames that go over the 50-move rule?
ThreadText: # What are the hardest pawnless endgames that go over the 50-move rule?
  
  (Asked by: username_0 on 2015-01-11)
  
  I know two pawnless endgames that go over the 50-move rule.
  
  King and 2 Bishops vs. King and Knight = 70 moves average.
  
  King, Rook and Bishop vs. King and 2 Knights = 200 move average.
  
  What others are there?
  
  **Tags:** endgame, 50-move-rule
  
  > **Comments:**
  > **username_1**: I feel the FIDE should reform the 50 move law & apply exceptions to these cases (would be epic a championship game decided in one of those endings!)  
  > **username_2**: @username_1 They did, for a while. It made very little difference, since these endgames come up very rarely in real life. So they moved back to a uniform 50 moves.  
  > **username_1**: Good to know, btw a similar question: http://chess.stackexchange.com/questions/351/what-is-the-status-for-seven-man-end-game-table-bases  
  > **username_0**: @username_1 not the same :l  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2015-01-12. Score: 3 | Accepted answer
  
  According to wikipedia <http://en.wikipedia.org/wiki/Pawnless_chess_endgame>, section "Endgames requiring more than 100 moves to win", the longest is
  
  R+N vs N+N = 243 moves
  with 78% of winning chances.
  
  R+B vs N+N = 223 moves
  with 96% of winning chances.
  
  R+N vs B+N = 190 moves
  with 72% winning chances.
  
  and the list goes on...
  
  Another way is looking at the database of mutual zugzwangs at <http://chess.jaet.org/cgi-bin/mzugs?sort=wmaxdtm> sorted by maxdtm (depth to conversion or mate).
  
  John Nunn's book "Secrets of pawnless endgames" (I love that book) in the 2nd editions expands coverage to some of the endings mentioned (although very briefly).
  
  
  ---
  
  ### Answer by username_3 on 2015-01-13. Score: 9
  
  If you mean "hardest" == "longest": There are 7-man table bases available and it is said that the longest pawnless ending takes 549 moves. It is KQB vs. KRBN.
  
  Resources: <http://tb7.chessok.com/articles/Top8DTM_eng>
  
  And in case you are too lazy to go through the moves by yourself :-): <http://tb7.chessok.com/probe/745/61>
  
  I think that is what is known today. I would not be surprised if even longer pawnless endings exists with 8 pieces on the board.
  
  > **Comments:**
  > **username_0**: Do you know what the winning chances are in this endgame if it was a random position?  
  > **username_3**: No, I don't have any other information on the winning chances for this endgame.  
  > **username_0**: ah, cuz that's what i kinda wanted to know, it had to be at least 90% winning chance  
  
  ---
  
  