Rebel 12No longer available !

This is the long awaited windows version of Ed Schröders Rebel program. Rebel 12 comes with the ChessPartner interface. The chess engine is programmed using the so called Winboard Protocol, this makes it possible to use the engine under other interfaces although it works best under the ChessPartner interface.

Rebel is one of the strongest and most complete chess programs in the world and absolute champion providing the maximum information on your screen, the visualization of the internal thinking process of the chess engine (Rebel's brain), more below.

Rebel is famous for its playing strength and is feared among the world top chess players, Rebel for example never lost a serious match against the top chess players of the world. Rebel until now played 4 chess matches against Super GM Arthur Yusupov (1997), Super GM Vishy Anand (1998), GM John van der Wiel (2001) and recently against top player Loek van Wely (2002) and only Super GM Loek van Wely was able to hold Rebel on a 2-2 score, Rebel won the other 3 matches.

The chess engine

The chess engine has greatly improved regarding positional understanding of the game of chess, the current version is an even more challenging opponent against strong human chess players. Added many new "Personality" parameters for serious engine tuning, more here...

The interface

The ChessPartner interface has been enhanced with a engine information window which provides detailed information about Rebels internal thinking process. 

The engine information window showing the search

The engine info window contains 10 information categories accessible through the tabs. In the picture the search information is shown.

Average depth : Rebel will maintain the average depth as long as the program is active. 

Search efficiency : Measuring Rebel's search algorithm, in general 90% and up is good, below 90% is not so good.

Ponder efficiency : Measuring Rebel's permanent brain guessing the move of the opponent, in general 50% is just great, 60% and up is regarded as very good./p>

Hash Table Usage : Column one, transpositions found for white in (K)ilobytes, Column 2 is for black, the third column is the percentage of the hash table that is filled.

TimeUsage : Rebel's estimated thinking time, the first column is the minimum time, the second column is the expected time when Rebel will move, very handy!

Positions : Column one, total positions searched so far, Column 2, the average number of positions searched per second also known as NPS (nodes per second).

The cdrom version of Rebel 12 comes with a giant chess tree of 55 million positions (size 600 Mb) in which the entire chess history of the last 160 years is stored. This database is for those who want to study chess openings but also can be used to increase Rebel's strength. Rebel's 55 million chess tree is the biggest in the world.

For optimal use and explanations of the EOC chess tree please visit the old Rebel pages.

All options from the DOS version are ported and can be set in the engine properties. In a nutshell: Option None -> View Chess Tree Only.

Option Moderate -> Rebel while calculating with a safe margin will rely on what is found in the chess tree.

Option Strong -> Rebel while calculating will strongly rely on what is found in the chess tree.

Option Book -> Rebel will use the entire chess tree as an opening book. Although this (overall) will limit Rebel's strength somewhat you on the other hand have the biggest opening book in the world at your availability.

Exporting results from the chess tree is simple, click right on the EOC1 (or EOC2, EOC3) window -> Copy All and the entire contents of that window is stored on the Windows clipboard. Sharing opening theory with your chess friends is easy now.

Many typical Rebel features are ported from DOS, to name a few:

Full book support, other opening books (even the user-books) can be used. The opening repertoire can be viewed and saved to a textfile.

Easy creating of EPD and PGN databases.

Using personalities (or styles).

Full EOC support.

Limited Rebel database support, import PGN, export PGN, Search Position. The latter is handy for opening study, the current position on the board is searched and games that match are reported and stored into a PGN file. Also the score and percentage are good indicators if the opening you are trying has a good perspective, see the picture.

Search Position is fast, on a XP-2400 it usually searches 12,500 games per second. Rebel 12 comes with a standard database of 110,000 games, the average elo rating of the players in the database is over 2500, thus the quality of search results are reliable. However if you purchased CENTURY 4 MEGA that came with 1,500,000 chess games you will have an even better investigation tool in your hands.

Clear Hash Table.

Extended Learner, this is something new similar to (DOS) CAT approach only better. When the option is active it will add large parts of games that went well to the opening book or use the data for a faster calculation next times.

Another fine new feature is that Rebel 12 automatically will store every game it plays in the file allgames.pgn

Greatly improved positional understanding. This makes the current version an even more challenging opponent against strong human chess players, consistent with the Rebel tradition.

Because the default setting of Rebel 12 is way too strong for 99% of all chess players in the world Rebel 12 comes with a large set of pre-programmed personalities (styles) that define the playing strength and playing style of Rebel 12, this to ensure the user not to lose every game without any chance. Pre-programmed personalities that lower Rebel's strength:

Novice: Rebel 12 will play as an absolute beginner, estimated elo rating 1200-1500.

Average Club Player: Rebel 12 will play as an average Club Player, estimated elo rating 1700-2000.

Strong Club Player: Rebel 12 will play as a strong Club Player, estimated elo rating 2000-2200.

Pre-programmed personalities that emulate the playing style of famous chess players:

Alexander Alekhine
Anatoli Karpov
Robert Fischer
Garry Kasparov

Judith Polgar
Michael Tal
Vishy Anand

The Rebel 12 chess engine has the possibility to run under other chess interfaces. Although this is not advised because we can not guarantee its proper behavior, we have noticed Rebel 12 to run smoothly under various other interfaces provided the steps from the readme file are taken.

The CD-ROM version includes a 55 million position opening book ( EOC ) and a Rebel database with 110.000 high quality games (ELO > 2500).