Sjeng : a chess-and-variants playing program

1. What is Sjeng ?

Sjeng was an attempt to create a bughouse & crazyhouse playing program that can attain a level comparable to what the best human players are capable of. Newer versions of Sjeng also play standard, suicide, giveaway and losers chess.

Deep Sjeng is a professional chess playing & analysis program, complete with interface, opening book, chess server access, personalities, multiprocessor and UCI support, and more. Its playing strength is over 2750 ELO on fast hardware. More information about Deep Sjeng here
 
2. What is Sjeng's status ?
 
It has successfully beaten players rated over 2600 points, including several titled GM's and IM's. One version of Sjeng even attained the first place in the crazyhouse players list on the Internet Chess Club (ICC), and the first place on the Free Internet Chess Server (FICS). Its crazyhouse rating currently fluctuates around 2300 points.

Sjeng is probably a bit weaker in bughouse than it is in crazyhouse. Most Sjeng's on the FICS have a rating of about 2000 points in bughouse, with a top of over 2200 points.

For standard chess, Sjeng's rating is probably about 2450 ELO. In suicide and losers chess Sjeng beats all but the very best humans, and will beat non-specialized programs easily.


3. What platforms does Sjeng run on ?
 
Sjeng was mostly written in ANSI C and should run on nearly any platform. Both Linux and Windows executables are available, as well as full sources.
 
4. What are Sjeng's requirements ?
 
Sjeng currently requires at least 16MB of RAM and a Pentium-grade CPU for decent bughouse play. It can be run on lesser hardware too, but performance will be disappointing.

For standard chess a 486 with minimal RAM is good enough. (The very latest versions are a bit more demading in terms of RAM, i.e. >=16Mb)

On an AMD Athlon XP 1800, Sjeng can currently search about 200.000-1.200.000 moves per second, depending on the variant, settings and position.

5. How do I play against Sjeng ?
 
Sjeng was written to use the WinBoard/XBoard interface available at http://www.tim-mann.org/chess.html.

Both WinBoard protocol 1 and 2 are supported. A lot of chess software supports WinBoard engines like Sjeng.

Zon Juan Jan has written free Windows interfaces for Sjeng, complete with easy-to-use installers. These allow you to play crazyhouse and suicide/givaway against Sjeng without having to set up Sjeng and WinBoard. They are available in the download area .
Screenshots are here .

Other interfaces that support Sjeng are Arena and SCID.

From version 12.10 on, the Universal Chess Interface (UCI) is also supported. This means that you can use Sjeng directly under Fritz 7 or newer, Shredder, ChessPartner (or Rebel Tiger), ChessAssistant and loads of other interfaces.

People that want to let Sjeng play on a chess server, please read these notes.

6. What are bughouse, crazyhouse, suicide, giveaway and losers ?

Bughouse is a form of chess which is played with 2 teams, each consisting of 2 players. Each player plays his opponent on a seperate board. If a piece is captured, the capturing player can pass it on to his partner, who can then drop the piece into his game and use it.

If you have never played bughouse before, you are really missing out on something. Try it, you'll like it.

Crazyhouse is identical to bughouse, but for 2 players and one board.

Suicide is a form of chess where the goal is to lose all your pieces. If you can capture, you must. The king can be captured just like a normal piece and you can promote a pawn to a king. In case of a stalemate the player with the least pieces wins. You cannot castle.

Giveaway is very similar to suicide, but you can castle and in case of a stalemate the stalemated player wins.

Losers is also similar to suicide and giveaway, but the king works like it does in normal chess. It cannot be captured, you cannot a promote a piece to a king and if you are in check you must get out. You win by losing all your pieces or by being checkmated.

7. Who wrote Sjeng ?
 
Sjeng was written by Gian-Carlo Pascutto with help from Adrien Regimbald, Daniel Clausen, Dann Corbit, Lenny Taelman, Ben Nye, Ronald De Man, David Dawson, Tim Foden and Georg von Zimmermann.

I can be reached at [email protected] or at FICS under the handle "Garf".

Comments and questions about or corrections to this web page can also be sent to the aforementioned address.