Answers.Body: <p>If you increase Rybka 3 Dynamic's contempt setting, it sacrifices more and more material in attractive style.</p>
  
  <p>The Fritz GUI (sold with Rybka, Komodo, Houdini, Junior, Shredder et al) includes a King's Attack slider in its Handicap and Fun dialog.  The Fritz 10 engine in particular avoided closed positions like the plague, and often played for mate.  It had an 'aggressive' parameter.</p>
  
  <p>Chess Tiger and Gambit Tiger (Chessbase or Lokasoft) had a "Suicidal" option under their Gambit Level parameter.</p>
  
  <p>Junior 7 had a 'sacrifices' parameter.</p>
  
  <p>Deep Sjeng 1.6 comes with gambitkitten, redshift and Tal personalities.</p>
  
  <p>Someone created a Dissident Aggressor personality for Zappa Mexico which is apparently quite wild.</p>
  
  <p>TheKing (a.k.a. Chessmaster) plays for mate even on its default settings.</p>
  
  <p>Amyan has a kinghunting parameter.</p>
  
  <p>Tao 5.6 tends to go for very complex positions with multiple pieces en prise.</p>
  
  <p>The old DOS program Chess System Tal had an attractive style with lots of sacs.</p>
  
  <p>Spark 1.0 and Fruit 2.3.1 had a King Attack parameter.</p>
  
  <p>The Kinghunter personality for Komodo only worked for version 1.0, and they changed the parameters after that.</p>
  
  <p>I think in general the programmers tried to make these engines both strong and aggressive.  All of these (with the exception of Chess System Tal) are at the level of an International Master or higher.  Engines below that designed to have a somewhat attractive style would include: Der Bringer, HeavyChess, Homer, Monarch and Trappy Beowulf.</p>
  
  <p>Another thing you could try is loading some of Chessbase's weaker engines, and increasing the King's Attack slider in Handicap and Fun.  Inmichess, Exchess, Comet and Capture R01 were all in the 2000-2400 range, and were sold by Chessbase in their Young Talents package.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-10-03T13:38:07.270Z
Answers.LastActivityDate: 2015-10-04T21:50:08.920Z
Answers.LastEditDate: 2015-10-04T21:50:08.920Z
Answers.UserDisplayName: A passerby
Answers.Body: <p>I have created such an engine at <a href="https://www.apronus.com/chess/romantic-chess-variant.htm" rel="nofollow noreferrer">https://www.apronus.com/chess/romantic-chess-variant.htm</a></p>
  
  <p>It has been modified to allow pawn promotion to knights only and to treat pawns very lightly when assessing the material balance. In fact, this creates a chess variant which I called <strong>Romantic Chess</strong> because it is meant to discourage playing for a better endgame as a winning strategy, effectively promoting direct mating attacks as the only realistic way to win the game.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-06-04T16:02:17.200Z
Answers.LastActivityDate: 2019-06-04T16:02:17.200Z
Answers.UserDisplayName: MichalRyszardWojcik
Answers.Body: <p>Many engines have adjustable parameters, which allow to alter their playing style. If you mess around it a bit, you can create whole 'engine personalities'... 
  Here, for example, someone though it interesting to create a personality called, the <a href="http://rybkaforum.net/cgi-bin/rybkaforum/topic_show.pl?tid=18970" rel="nofollow noreferrer">Komodo Kinghunter</a>. Apparently, it does exactly what you are looking for - plays aggressively and not necessarily optimally. Note that I have not tested it myself.</p>
  
  <p>It's different for different engines (I remember most of these at least used to be configurable in stockfish) and graphical interfaces, but 
  some typical factors one can usually twiddle with (at worst by going to source code and recompiling) are:</p>
  
  <p><strong>Contempt Factor</strong></p>
  
  <blockquote>
    <p>The Contempt Factor reflects the estimated superiority/inferiority of the program over its opponent. The Contempt factor is assigned as draw score to avoid (early) draws against apparently weaker opponents, or to prefer draws versus stronger opponents otherwise.</p>
  </blockquote>
  
  <p>Additionally, if the engine has high contempt for its opponent, it might engage in more attacking style.</p>
  
  <p><strong>Pawn structure</strong></p>
  
  <blockquote>
    <p>Pawn structure is a term used to describe the positions of all the pawns on the board, ignoring all other pieces. Pawn structure encompasses a broad range of ideas, from the general shape of the pawns (such as closed or open) to specific characteristics of individual pawns.</p>
  </blockquote>
  
  <p>So here there's a wide range of things to change engines evaluations for - double pawns, passed pawns, general structure, exchanges etc.</p>
  
  <p><strong>Mobility</strong>
  A factor for how much the engine will value the piece mobility - I suppose more mobility leads to more attacking and unpredictable positions.</p>
  
  <p><strong>Aggressiveness</strong>
  Self-explanatory; allows to make the engine more or less aggressive.</p>
  
  <p><strong>Cowardice</strong>
  Self-explanatory; allows to define how defensive towards its own king the program should be.</p>
  
  <p><a href="https://chessprogramming.wikispaces.com/" rel="nofollow noreferrer">Source for quotes</a></p>
  
  <p><strong>EDIT: I was made aware (per Student T's comment), that the engine I initially posted below is not attractive at all and in fact a clone of Rybka. I guess it was too good to be true!</strong></p>
  
  <p>If you are reluctant to do all this fiddling yourself, <a href="http://www.vitruviuschess.com/index.php" rel="nofollow noreferrer">here's</a> an engine which (again, I have not tried it myself, so cannot substantiate these claims in any way):</p>
  
  <blockquote>
    <p>Thanks to its finely tuned positional vision, Vitruvius shows a readiness to sacrifice a pawn or two, the exchange and sometimes even a whole piece, for purely positional compensation.</p>
  </blockquote>
  
  <p>And named among its strengths:</p>
  
  <blockquote>
    <p>Playing strength above the 3100ELOmark; Detects and exploits zugzwang positions; Very human and speculative approach to the game</p>
  </blockquote>
  
  <p>Also of interest: <a href="http://www.vitruviuschess.com/article/Human-Test.html" rel="nofollow noreferrer">this Vitruvius article</a></p>
  
  <p>Unfortunately, it is not free.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T11:56:50.883Z
Answers.Text: To clarify your comment about Stockfish: most of these options aren't present in Stockfish 6, but they are present in Stockfish 5, which is still available via the [Stockfish website](http://stockfishchess.org/).
Answers.UserDisplayName: Stephen
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T12:11:34.993Z
Answers.Text: Vitruvius is a well known clone of an reverse-engineered Rybka 3.0. It's certainly not attractive in anything. The website says it to make you to do a sale.
Answers.UserDisplayName: SmallChess
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T12:25:42.760Z
Answers.Text: @Stephen Good to know! I suspected they might have removed it from newest versions, they did so in a phone app that runs on stockfish.
Answers.UserDisplayName: GloriaVictis
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T12:27:11.213Z
Answers.Text: @StudentT Ah, that's a valuable piece of information. Thank you! I edited the post accordingly.
Answers.UserDisplayName: GloriaVictis
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T12:28:50.673Z
Answers.Text: @GloriaVicits It's indeed true that the two Stockfish phone apps don't support personality (Stockfish and SmallFish). Fortunately, I'll add back the personality to the SmallFish app. (I'm the developer for SmallFish).
Answers.UserDisplayName: SmallChess
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T12:30:36.547Z
Answers.Text: I think all options apart from Contempt have been stripped off since Stockfish 6.
Answers.UserDisplayName: SmallChess
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T12:30:39.490Z
Answers.Text: @StudentT That is great news; possibility of personalizing the engine's play style is a huge boost to the app's attractiveness.
Answers.UserDisplayName: GloriaVictis
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-04-06T12:37:49.647Z
Answers.Text: @stephen thanks for your tip. I currently try out stockfish 5.
Answers.UserDisplayName: Peter
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2015-04-06T10:41:31.773Z
Answers.LastActivityDate: 2019-06-05T18:45:00.913Z
Answers.LastEditDate: 2019-06-05T18:45:00.913Z
Answers.UserDisplayName: GloriaVictis
Body: <p>Does anyone know a chess engine that is not programmed to be as strong as
   possible, but to play "attractive" chess ?</p>
  
  <p>The program should have an aggressive style and play for mate attacks, even
   if the attacking moves are not quite optimal. Or at least, the program
   should trade some panws early to avoid very closed positions which tend
   to take an eternity between engines to be finished.</p>
  
  <p>On the other hand, the program should not play too weak. The rating should
   at least be about 2000 Elo.</p>
  
  <p>Does anyone know such an engine ?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-04-06T09:49:29.027Z
Comments.Text: Use the tag *engine* instead of *software* when the question is about engines.
Comments.UserDisplayName: Dag Oskar Madsen
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-04-10T01:44:14.457Z
Comments.Text: I've been fiddling with stockfish to convince it attacking with it's king is a good idea, so that it can play the bongcloud opening properly. Is that what you're looking for? I can't think of anything that defines "attractive chess" better than the bongcloud :)
Comments.UserDisplayName: QuadmasterXLII
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2024-06-27T10:42:08.083Z
Comments.Text: Related question: [Is there an engine (setting) that favours "reckless" moves?](https://chess.stackexchange.com/q/40871/14678)
Comments.UserDisplayName: Cyriac Antony
Tags: <engines><aggressive-play><attack>
Title: Engine not necessarily playing strong but "attractive"
ThreadText: # Engine not necessarily playing strong but "attractive"
  
  (Asked by: username_0 on 2015-04-06)
  
  Does anyone know a chess engine that is not programmed to be as strong as
  possible, but to play "attractive" chess ?
  
  The program should have an aggressive style and play for mate attacks, even
  if the attacking moves are not quite optimal. Or at least, the program
  should trade some panws early to avoid very closed positions which tend
  to take an eternity between engines to be finished.
  
  On the other hand, the program should not play too weak. The rating should
  at least be about 2000 Elo.
  
  Does anyone know such an engine ?
  
  **Tags:** engines, aggressive-play, attack
  
  > **Comments:**
  > **username_1**: Use the tag *engine* instead of *software* when the question is about engines.  
  > **username_2**: I've been fiddling with stockfish to convince it attacking with it's king is a good idea, so that it can play the bongcloud opening properly. Is that what you're looking for? I can't think of anything that defines "attractive chess" better than the bongcloud :)  
  > **username_3**: Related question: [Is there an engine (setting) that favours "reckless" moves?](https://chess.stackexchange.com/q/40871/14678)  
  
  ---
  
  ## 3 answers
  
  ### Answer by username_6 on 2015-04-06. Score: 7 | Accepted answer
  
  Many engines have adjustable parameters, which allow to alter their playing style. If you mess around it a bit, you can create whole 'engine personalities'...
  Here, for example, someone though it interesting to create a personality called, the [Komodo Kinghunter](http://rybkaforum.net/cgi-bin/rybkaforum/topic_show.pl?tid=18970). Apparently, it does exactly what you are looking for - plays aggressively and not necessarily optimally. Note that I have not tested it myself.
  
  It's different for different engines (I remember most of these at least used to be configurable in stockfish) and graphical interfaces, but
  some typical factors one can usually twiddle with (at worst by going to source code and recompiling) are:
  
  **Contempt Factor**
  
  > The Contempt Factor reflects the estimated superiority/inferiority of the program over its opponent. The Contempt factor is assigned as draw score to avoid (early) draws against apparently weaker opponents, or to prefer draws versus stronger opponents otherwise.
  
  Additionally, if the engine has high contempt for its opponent, it might engage in more attacking style.
  
  **Pawn structure**
  
  > Pawn structure is a term used to describe the positions of all the pawns on the board, ignoring all other pieces. Pawn structure encompasses a broad range of ideas, from the general shape of the pawns (such as closed or open) to specific characteristics of individual pawns.
  
  So here there's a wide range of things to change engines evaluations for - double pawns, passed pawns, general structure, exchanges etc.
  
  **Mobility**
  A factor for how much the engine will value the piece mobility - I suppose more mobility leads to more attacking and unpredictable positions.
  
  **Aggressiveness**
  Self-explanatory; allows to make the engine more or less aggressive.
  
  **Cowardice**
  Self-explanatory; allows to define how defensive towards its own king the program should be.
  
  [Source for quotes](https://chessprogramming.wikispaces.com/)
  
  **EDIT: I was made aware (per Student T's comment), that the engine I initially posted below is not attractive at all and in fact a clone of Rybka. I guess it was too good to be true!**
  
  If you are reluctant to do all this fiddling yourself, [here's](http://www.vitruviuschess.com/index.php) an engine which (again, I have not tried it myself, so cannot substantiate these claims in any way):
  
  > Thanks to its finely tuned positional vision, Vitruvius shows a readiness to sacrifice a pawn or two, the exchange and sometimes even a whole piece, for purely positional compensation.
  
  And named among its strengths:
  
  > Playing strength above the 3100ELOmark; Detects and exploits zugzwang positions; Very human and speculative approach to the game
  
  Also of interest: [this Vitruvius article](http://www.vitruviuschess.com/article/Human-Test.html)
  
  Unfortunately, it is not free.
  
  > **Comments:**
  > **username_7**: To clarify your comment about Stockfish: most of these options aren't present in Stockfish 6, but they are present in Stockfish 5, which is still available via the [Stockfish website](http://stockfishchess.org/).  
  > **username_8**: Vitruvius is a well known clone of an reverse-engineered Rybka 3.0. It's certainly not attractive in anything. The website says it to make you to do a sale.  
  > **username_6**: @username_7 Good to know! I suspected they might have removed it from newest versions, they did so in a phone app that runs on stockfish.  
  > **username_6**: @StudentT Ah, that's a valuable piece of information. Thank you! I edited the post accordingly.  
  > **username_8**: @GloriaVicits It's indeed true that the two Stockfish phone apps don't support personality (Stockfish and SmallFish). Fortunately, I'll add back the personality to the SmallFish app. (I'm the developer for SmallFish).  
  > **username_8**: I think all options apart from Contempt have been stripped off since Stockfish 6.  
  > **username_6**: @StudentT That is great news; possibility of personalizing the engine's play style is a huge boost to the app's attractiveness.  
  > **username_0**: @stephen thanks for your tip. I currently try out stockfish 5.  
  
  ---
  
  ### Answer by username_4 on 2015-10-03. Score: 5
  
  If you increase Rybka 3 Dynamic's contempt setting, it sacrifices more and more material in attractive style.
  
  The Fritz GUI (sold with Rybka, Komodo, Houdini, Junior, Shredder et al) includes a King's Attack slider in its Handicap and Fun dialog. The Fritz 10 engine in particular avoided closed positions like the plague, and often played for mate. It had an 'aggressive' parameter.
  
  Chess Tiger and Gambit Tiger (Chessbase or Lokasoft) had a "Suicidal" option under their Gambit Level parameter.
  
  Junior 7 had a 'sacrifices' parameter.
  
  Deep Sjeng 1.6 comes with gambitkitten, redshift and Tal personalities.
  
  Someone created a Dissident Aggressor personality for Zappa Mexico which is apparently quite wild.
  
  TheKing (a.k.a. Chessmaster) plays for mate even on its default settings.
  
  Amyan has a kinghunting parameter.
  
  Tao 5.6 tends to go for very complex positions with multiple pieces en prise.
  
  The old DOS program Chess System Tal had an attractive style with lots of sacs.
  
  Spark 1.0 and Fruit 2.3.1 had a King Attack parameter.
  
  The Kinghunter personality for Komodo only worked for version 1.0, and they changed the parameters after that.
  
  I think in general the programmers tried to make these engines both strong and aggressive. All of these (with the exception of Chess System Tal) are at the level of an International Master or higher. Engines below that designed to have a somewhat attractive style would include: Der Bringer, HeavyChess, Homer, Monarch and Trappy Beowulf.
  
  Another thing you could try is loading some of Chessbase's weaker engines, and increasing the King's Attack slider in Handicap and Fun. Inmichess, Exchess, Comet and Capture R01 were all in the 2000-2400 range, and were sold by Chessbase in their Young Talents package.
  
  
  ---
  
  ### Answer by username_5 on 2019-06-04. Score: 0
  
  I have created such an engine at <https://www.apronus.com/chess/romantic-chess-variant.htm>
  
  It has been modified to allow pawn promotion to knights only and to treat pawns very lightly when assessing the material balance. In fact, this creates a chess variant which I called **Romantic Chess** because it is meant to discourage playing for a better endgame as a winning strategy, effectively promoting direct mating attacks as the only realistic way to win the game.
  
  
  ---
  
  