Answers.Body: <p>I've never used it myself, but I believe that <a href="http://poincare.matf.bg.ac.rs/~andrew/suicide/StanGold/wizard3_1.htm" rel="nofollow">Wizard</a> is a strong and free Loser's Chess engine. An <a href="http://poincare.matf.bg.ac.rs/~andrew/suicide/StanGold/top20.htm" rel="nofollow">undated reference table</a> on the same website shows that Wizard used to be one of the strongest Losers engines on FICS - however, I understand that the creator passed away many years ago so it may be outdated.</p>
  
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Answers.CreationDate: 2013-06-27T20:11:18.137Z
Answers.Text: I am familiar with that web site. It appears that Wizard does NOT play Loser's Chess, but instead "Losing Chess" or Suicide Chess.
Answers.UserDisplayName: Rick G
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Answers.Text: Ah, I apologize for my misinformed answer. Thank you for letting me know. I'll provide an edit as soon as I find another suitable engine.
Answers.UserDisplayName: Andrew Ng
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Answers.UserDisplayName: Andrew Ng
Answers.Body: <p>The <b><a href="http://hgm.nubati.net/alien.html" rel="nofollow">WinBoard Alien GUI</a></b> is reputedly better suited to playing chess variants than the standard WinBoard is, but that's just an observation.<br></p>
  
  <p>As to engines that play Losers Chess within a WinBoard environment, it seems that the answer is unfortunately no: Sjeng seems to be the strongest of these (within context), though at least OliThink seems likely to give you a greater challenge than you might from get Pulsar.<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The results of several competitions (w/ environment data included) in Losers Chess (each with some changes in competing engines involved) are posted at the ImmortalChess forum ("<i><a href="http://immortalchess.net/forum/archive/index.php/t-12308.html" rel="nofollow">Losers tournament</a></i>" contains the pertinent tables, while the <a href="http://immortalchess.net/forum/archive/index.php/t-12308-p-2.html" rel="nofollow">third</a> &amp; <a href="http://immortalchess.net/forum/archive/index.php/t-12308-p-3.html" rel="nofollow">fourth</a> pages of that thread contain two tables for their "<i>Suicide chess tournament</i>" from which to infer Nebiyu's possible strength by comparison).</p>
  
  <p>Sequenced in accordance with the engines' <i>normalized</i> mean averages of those tournaments:</p>
  
  <ol>
  <li><p><a href="https://sjeng.org/download.html" rel="nofollow">Sjeng 11.2</a> &nbsp;. . . . . . . . . . . . . . . . . . . . . . . . . 0.885416(7)</p></li>
  <li><p><a href="http://kirr.homeunix.org/chess/engines/Norbert%27s%20collection/OliThink%20(Compilation)/" rel="nofollow">Olithink 2.2.1</a> [OliPow] <b><i>note A</i></b> &nbsp;&nbsp;. . . . . . . . . 0.5625(0)</p></li>
  <li><p><a href="http://www.lanternchess.com/pulsar/" rel="nofollow">Pulsar 2009-9b</a> &nbsp;. . . . . . . . . . . . . . . . . . . . . 0.411458(3)</p></li>
  <li><p><a href="http://web.archive.org/web/20070826142516/http://www.seanet.com/~brucemo/gerbil/gerbil.htm" rel="nofollow">Gerbil 02</a> <b><i>note B</i></b> &nbsp;. . . . . . . . . . . . . . . . . . . . 0.3541(6)</p></li>
  <li><p><a href="http://kirr.homeunix.org/chess/engines/Jim%20Ablett/KKFCHESS/" rel="nofollow">KKF 2.6.6</a> . . . . . . . . . . . . . . . . . . . . . . . . . . 0.31708(3)</p></li>
  <li><p><a href="https://sites.google.com/site/dshawul/" rel="nofollow">Nebiyu 1.41</a> <b><i>notes C.x</i></b> . . . . . . . . . . . . . . . . UNDEF. <i>(0.275(+), <b>est.</b>)</i></p></li>
  <li><p><a href="https://github.com/pychess/pychess/wiki/StauntonRelease" rel="nofollow">PyChess</a> <b><i>note D</i></b> &nbsp;. . . . . . . . . . . . . . . . . . . . UNDEF.</p></li>
  </ol>
  
  <hr>
  
  <p><b>Notes:</b></p>
  
  <ul>
  <li><p><b>A:</b> multiple other versions of OliThink 2.2.1 (in addition to those in the normalized list's link) can be had <a href="http://home.arcor.de/dreamlike/chess/index.html" rel="nofollow">elsewhere</a> (at the bottom, in the “Older versions:” section).</p></li>
  <li><p><b>B:</b> Gerbil ver.s 01 &amp; 02 "...<i><a href="http://immortalchess.net/forum/archive/index.php/t-12308.html" rel="nofollow">come with a separate executable for loser's chess</a></i>...".</p></li>
  <li><p><b>C:</b> Nebiyu Alien has many additional [user defined] .ini files available as a <a href="http://www.solidfiles.com/d/67f321a0a9/" rel="nofollow">collective package</a> or <a href="http://immortalchess.net/forum/showthread.php?t=12308" rel="nofollow">individually</a>.</p></li>
  <li><p><b>C.1:</b> Nebiyu can play Losers Chess, if you <a href="http://immortalchess.net/forum/archive/index.php/t-12308.html" rel="nofollow">edit the winboard.ini</a> (after which, “<i>With -W (w17) </i>[in the command line option]<i> losers chess it works fine...</i>”).</p></li>
  <li><p><b>C.2:</b> Note that Nebiyu might be “<i><a href="http://immortalchess.net/forum/archive/index.php/t-12308-p-3.html" rel="nofollow">...playing atomic losers chess.</a></i>” (later attested <i>to the contrary</i> by another).</p></li>
  <li><p><b>D:</b> PyChess wasn't one of the competitors, but <a href="https://github.com/pychess/pychess/wiki/StauntonRelease" rel="nofollow">can</a> play Losers Chess, though it might be <a href="https://groups.google.com/forum/#!topic/pychess-people/1gq5Hsin4JI" rel="nofollow">too weak an engine</a> (in context of Losers Chess) to consider modifying for this purpose.</p></li>
  </ul>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-07-13T00:34:57.217Z
Answers.Text: Great information here - I did not know of WinBoard Alien. I read through the VERY long post at immortalchess.net which contained the Losers tournament results. I look forward to trying out OliThink.
Answers.UserDisplayName: Rick G
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Answers.LastEditDate: 2016-07-04T02:50:17.963Z
Answers.UserDisplayName: Charles Rockafellor
Body: <p>I often use the Pulsar engine to analyze my Atomic games for better play (post-mortem). I definitely learn something, since I am not as smart as Pulsar. I am interested in doing the same thing for Losers chess. Pulsar is not very good at Losers, but Sjeng is better at this variant.</p>
  
  <p>I use both Pulsar and Sjeng under the WinBoard interface. Does anyone know of stronger engines that play Losers chess? I have Googled for several days, did not find any. Both Pulsar and Sjeng are free, but I would be willing to buy better software.</p>
  
  <p><strong>PLEASE NOTE</strong>
  Many sites have confusing terminology for variants. Losers chess is not the same as Suicide or Giveaway. In Losers chess, the King can be checkmated, and you must respond to check. This makes a big difference in the strategy for Losers chess compared to Suicide chess.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-11-27T13:34:51.000Z
Comments.Text: Does this answer your question? [Losers Chess variant engine](https://chess.stackexchange.com/questions/19539/losers-chess-variant-engine)
Comments.UserDisplayName: Minot
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-11-27T15:52:17.540Z
Comments.Text: Thank you, @Minot, for bringing this to the moderators' attention. However, note that if question A is asked at time t and then question B is asked at time t+dt then B is a duplicate of A and not vice versa.
Comments.UserDisplayName: Brian Towers
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-11-27T18:03:42.920Z
Comments.Text: @BrianTowers I know that but the answers to this question is pretty outdated. That's why I flagged the opposite way. Maybe they can be merged if it is possible. I don't know.
Comments.UserDisplayName: Minot
Tags: <engines><chess-variants><losing-chess>
Title: Chess engine - Losers variant
ThreadText: # Chess engine - Losers variant
  
  (Asked by: username_0 on 2012-12-25)
  
  I often use the Pulsar engine to analyze my Atomic games for better play (post-mortem). I definitely learn something, since I am not as smart as Pulsar. I am interested in doing the same thing for Losers chess. Pulsar is not very good at Losers, but Sjeng is better at this variant.
  
  I use both Pulsar and Sjeng under the WinBoard interface. Does anyone know of stronger engines that play Losers chess? I have Googled for several days, did not find any. Both Pulsar and Sjeng are free, but I would be willing to buy better software.
  
  **PLEASE NOTE**
  Many sites have confusing terminology for variants. Losers chess is not the same as Suicide or Giveaway. In Losers chess, the King can be checkmated, and you must respond to check. This makes a big difference in the strategy for Losers chess compared to Suicide chess.
  
  **Tags:** engines, chess-variants, losing-chess
  
  > **Comments:**
  > **username_1**: Does this answer your question? [Losers Chess variant engine](https://chess.stackexchange.com/questions/19539/losers-chess-variant-engine)  
  > **username_2**: Thank you, @username_1, for bringing this to the moderators' attention. However, note that if question A is asked at time t and then question B is asked at time t+dt then B is a duplicate of A and not vice versa.  
  > **username_1**: @username_2 I know that but the answers to this question is pretty outdated. That's why I flagged the opposite way. Maybe they can be merged if it is possible. I don't know.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_3 on 2013-06-26. Score: 3
  
  I've never used it myself, but I believe that [Wizard](http://poincare.matf.bg.ac.rs/~username_3/suicide/StanGold/wizard3_1.htm) is a strong and free Loser's Chess engine. An [undated reference table](http://poincare.matf.bg.ac.rs/~username_3/suicide/StanGold/top20.htm) on the same website shows that Wizard used to be one of the strongest Losers engines on FICS - however, I understand that the creator passed away many years ago so it may be outdated.
  
  > **Comments:**
  > **username_0**: I am familiar with that web site. It appears that Wizard does NOT play Loser's Chess, but instead "Losing Chess" or Suicide Chess.  
  > **username_3**: Ah, I apologize for my misinformed answer. Thank you for letting me know. I'll provide an edit as soon as I find another suitable engine.  
  
  ---
  
  ### Answer by username_4 on 2016-07-04. Score: 2
  
  The **[WinBoard Alien GUI](http://hgm.nubati.net/alien.html)** is reputedly better suited to playing chess variants than the standard WinBoard is, but that's just an observation.
  
  As to engines that play Losers Chess within a WinBoard environment, it seems that the answer is unfortunately no: Sjeng seems to be the strongest of these (within context), though at least OliThink seems likely to give you a greater challenge than you might from get Pulsar.  
       The results of several competitions (w/ environment data included) in Losers Chess (each with some changes in competing engines involved) are posted at the ImmortalChess forum ("*[Losers tournament](http://immortalchess.net/forum/archive/index.php/t-12308.html)*" contains the pertinent tables, while the [third](http://immortalchess.net/forum/archive/index.php/t-12308-p-2.html) & [fourth](http://immortalchess.net/forum/archive/index.php/t-12308-p-3.html) pages of that thread contain two tables for their "*Suicide chess tournament*" from which to infer Nebiyu's possible strength by comparison).
  
  Sequenced in accordance with the engines' *normalized* mean averages of those tournaments:
  
  1. [Sjeng 11.2](https://sjeng.org/download.html)  . . . . . . . . . . . . . . . . . . . . . . . . . 0.885416(7)
  2. [Olithink 2.2.1](http://kirr.homeunix.org/chess/engines/Norbert%27s%20collection/OliThink%20(Compilation)/) [OliPow] ***note A***   . . . . . . . . . 0.5625(0)
  3. [Pulsar 2009-9b](http://www.lanternchess.com/pulsar/)  . . . . . . . . . . . . . . . . . . . . . 0.411458(3)
  4. [Gerbil 02](http://web.archive.org/web/20070826142516/http://www.seanet.com/~brucemo/gerbil/gerbil.htm) ***note B***  . . . . . . . . . . . . . . . . . . . . 0.3541(6)
  5. [KKF 2.6.6](http://kirr.homeunix.org/chess/engines/Jim%20Ablett/KKFCHESS/) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.31708(3)
  6. [Nebiyu 1.41](https://sites.google.com/site/dshawul/) ***notes C.x*** . . . . . . . . . . . . . . . . UNDEF. *(0.275(+), **est.**)*
  7. [PyChess](https://github.com/pychess/pychess/wiki/StauntonRelease) ***note D***  . . . . . . . . . . . . . . . . . . . . UNDEF.
  
  ---
  
  **Notes:**
  
  * **A:** multiple other versions of OliThink 2.2.1 (in addition to those in the normalized list's link) can be had [elsewhere](http://home.arcor.de/dreamlike/chess/index.html) (at the bottom, in the “Older versions:” section).
  * **B:** Gerbil ver.s 01 & 02 "...*[come with a separate executable for loser's chess](http://immortalchess.net/forum/archive/index.php/t-12308.html)*...".
  * **C:** Nebiyu Alien has many additional [user defined] .ini files available as a [collective package](http://www.solidfiles.com/d/67f321a0a9/) or [individually](http://immortalchess.net/forum/showthread.php?t=12308).
  * **C.1:** Nebiyu can play Losers Chess, if you [edit the winboard.ini](http://immortalchess.net/forum/archive/index.php/t-12308.html) (after which, “*With -W (w17)* [in the command line option] *losers chess it works fine...*”).
  * **C.2:** Note that Nebiyu might be “*[...playing atomic losers chess.](http://immortalchess.net/forum/archive/index.php/t-12308-p-3.html)*” (later attested *to the contrary* by another).
  * **D:** PyChess wasn't one of the competitors, but [can](https://github.com/pychess/pychess/wiki/StauntonRelease) play Losers Chess, though it might be [too weak an engine](https://groups.google.com/forum/#!topic/pychess-people/1gq5Hsin4JI) (in context of Losers Chess) to consider modifying for this purpose.
  
  > **Comments:**
  > **username_0**: Great information here - I did not know of WinBoard Alien. I read through the VERY long post at immortalchess.net which contained the Losers tournament results. I look forward to trying out OliThink.  
  
  ---
  
  