Answers.Body: <p>Sjeng supports losers chess too since <a href="https://www.sjeng.org/news.html" rel="nofollow noreferrer">release 9</a>.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-29T17:13:57.957Z
Answers.Text: I lost the first game so I called it strong! 
Answers.UserDisplayName: Jacques Gaudin
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-30T05:56:58.577Z
Answers.Text: Modified comment: to be fair https://chessforeva.appspot.com/SjengBoard.htm uses a javascript version (limited in terms of power and memory) and plays ok.
Answers.UserDisplayName: Déjà vu
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-28T20:32:15.690Z
Answers.LastActivityDate: 2017-12-28T20:32:15.690Z
Answers.UserDisplayName: Jacques Gaudin
Answers.Body: <blockquote>
    <p><a href="https://github.com/ddugovic/Stockfish" rel="noreferrer">https://github.com/ddugovic/Stockfish</a></p>
  </blockquote>
  
  <p>has what you want. Not an offical version, but should be stable for production.</p>
  
  <p><a href="https://i.sstatic.net/a67Kx.png" rel="noreferrer"><img src="https://i.sstatic.net/a67Kx.png" alt="enter image description here"></a></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-29T02:46:41.137Z
Answers.Text: This version of Stockfish supports both Suicide chess (no check / checkmate, give away all pieces) as well as Loser chess (give away all pieces, but includes check / checkmate).
Answers.UserDisplayName: Rick G
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-04T23:15:25.080Z
Answers.Text: @RingØ What do you mean by endgame against king only? In losers chess the game immediately ends if one side only has the bare king, so are you talking about losers or antichess? If Stockfish is really bad at playing certain endgames, please let me know or create an issue at https://github.com/ddugovic/Stockfish/issues, then we will try to investigate.
Answers.UserDisplayName: Fabian Fichter
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-05T01:58:47.733Z
Answers.Text: @FabianFichter Thanks for contributing. Indeed, my phrasing is confusing. It's actually King with 1 (or 2) pawns only, blocked by 1 (or 2) SF pawns, SF having more material, still (typically the required material to win that kind of game: R + B for instance). In this case, SF repeats configurations endlessly (while at depth 28). I was (also) interested in programming a simple algo, but that endgame part seems to require a specific laborious implementation.
Answers.UserDisplayName: Déjà vu
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-05T09:59:52.490Z
Answers.Text: @RingØ For losers chess we have not implemented any specific endgame evaluation functions, partly because I simply do not have much experience with losers chess (in contrast to giveaway/suicide chess). I have just tested positions like 8/8/8/1p3k2/1P6/5KR1/8/4B3 w - - 0 1, and SF finds "mate" quite quickly at depth 22. Could you please provide a sample position where SF has difficulties winning it? And if you know some basic ideas how to win such endgames, that would also be nice to know. To me it seems like sacrificing a piece, blocking the pawn and promoting your own pawn is the idea.
Answers.UserDisplayName: Fabian Fichter
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-05T14:07:29.083Z
Answers.Text: @FabianFichter Well, I tried various positions at depth 28, and SF is strikingly strong! Could only get a draw from `7K/p1p5/P1P5/8/8/8/8/7k b` or `1b5K/p1p5/P1P5/8/8/8/8/7k b` (how the `b` went to `b8`  is another story). Tried many configs and depths at the time and possibly the settings were different, so removed my previous wrong comment. SF does a very good job in Losers endgames, actually, and that's amazing if it's not even specifically programmed for that.
Answers.UserDisplayName: Déjà vu
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-05T17:00:10.067Z
Answers.Text: Ok, thanks, that is nice to hear. If you still find something fishy, please let us know.
Answers.UserDisplayName: Fabian Fichter
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-28T13:35:30.133Z
Answers.LastActivityDate: 2017-12-28T13:35:30.133Z
Answers.UserDisplayName: SmallChess
Body: <p>Is there a strong Losers chess variant engine? </p>
  
  <p>I had a look at stockfish, but it doesn't support Losers chess, seemingly.</p>
  
  <p>(to be used on a Linux platform)</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-12-28T06:21:39.830Z
Comments.Text: I think it does. Not the offical version.
Comments.UserDisplayName: SmallChess
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-12-28T15:50:25.253Z
Comments.Text: On lichess you can also start an analysis session with a specialised Stockfish for each chess variant. Here's the link for Losers chess (there known as Antichess): https://lichess.org/analysis/antichess
Comments.UserDisplayName: Ellie
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-12-29T02:47:52.937Z
Comments.Text: The version of Stockfish at lichess.org supports Anti-chess aka Suicide chess (no check / checkmate, give away all pieces). Technically not the same variant as Losers chess (give away all pieces, but includes check / checkmate).
Comments.UserDisplayName: Rick G
Tags: <engines><chess-variants><linux><losing-chess>
Title: Losers Chess variant engine
ThreadText: # Losers Chess variant engine
  
  (Asked by: username_0 on 2017-12-28)
  
  Is there a strong Losers chess variant engine?
  
  I had a look at stockfish, but it doesn't support Losers chess, seemingly.
  
  (to be used on a Linux platform)
  
  **Tags:** engines, chess-variants, linux, losing-chess
  
  > **Comments:**
  > **username_1**: I think it does. Not the offical version.  
  > **username_2**: On lichess you can also start an analysis session with a specialised Stockfish for each chess variant. Here's the link for Losers chess (there known as Antichess): https://lichess.org/analysis/antichess  
  > **username_3**: The version of Stockfish at lichess.org supports Anti-chess aka Suicide chess (no check / checkmate, give away all pieces). Technically not the same variant as Losers chess (give away all pieces, but includes check / checkmate).  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2017-12-28. Score: 8 | Accepted answer
  
  > <https://github.com/ddugovic/Stockfish>
  
  has what you want. Not an offical version, but should be stable for production.
  
  [![enter image description here](https://i.sstatic.net/a67Kx.png)](https://i.sstatic.net/a67Kx.png)
  
  > **Comments:**
  > **username_3**: This version of Stockfish supports both Suicide chess (no check / checkmate, give away all pieces) as well as Loser chess (give away all pieces, but includes check / checkmate).  
  > **username_5**: @RingØ What do you mean by endgame against king only? In losers chess the game immediately ends if one side only has the bare king, so are you talking about losers or antichess? If Stockfish is really bad at playing certain endgames, please let me know or create an issue at https://github.com/ddugovic/Stockfish/issues, then we will try to investigate.  
  > **username_0**: @FabianFichter Thanks for contributing. Indeed, my phrasing is confusing. It's actually King with 1 (or 2) pawns only, blocked by 1 (or 2) SF pawns, SF having more material, still (typically the required material to win that kind of game: R + B for instance). In this case, SF repeats configurations endlessly (while at depth 28). I was (also) interested in programming a simple algo, but that endgame part seems to require a specific laborious implementation.  
  > **username_5**: @RingØ For losers chess we have not implemented any specific endgame evaluation functions, partly because I simply do not have much experience with losers chess (in contrast to giveaway/suicide chess). I have just tested positions like 8/8/8/1p3k2/1P6/5KR1/8/4B3 w - - 0 1, and SF finds "mate" quite quickly at depth 22. Could you please provide a sample position where SF has difficulties winning it? And if you know some basic ideas how to win such endgames, that would also be nice to know. To me it seems like sacrificing a piece, blocking the pawn and promoting your own pawn is the idea.  
  > **username_0**: @FabianFichter Well, I tried various positions at depth 28, and SF is strikingly strong! Could only get a draw from `7K/p1p5/P1P5/8/8/8/8/7k b` or `1b5K/p1p5/P1P5/8/8/8/8/7k b` (how the `b` went to `b8`  is another story). Tried many configs and depths at the time and possibly the settings were different, so removed my previous wrong comment. SF does a very good job in Losers endgames, actually, and that's amazing if it's not even specifically programmed for that.  
  > **username_5**: Ok, thanks, that is nice to hear. If you still find something fishy, please let us know.  
  
  ---
  
  ### Answer by username_4 on 2017-12-28. Score: 4
  
  Sjeng supports losers chess too since [release 9](https://www.sjeng.org/news.html).
  
  > **Comments:**
  > **username_4**: I lost the first game so I called it strong!   
  > **username_0**: Modified comment: to be fair https://chessforeva.appspot.com/SjengBoard.htm uses a javascript version (limited in terms of power and memory) and plays ok.  
  
  ---
  
  