- REBEL10.5 -

On the REBEL-CP cdrom you also will find the latest version of REBEL 10.5 the successor REBEL10. The development on the DOS GUI has been stopped although a few minor features have been added.

The main improvements are based on making the engine stronger, more attractive but most of all more flexible. It's our understanding that today's chess programs are so incredible strong that more and more people are using a chess program in another way than 3-4 years ago. The Chess 2010 Opinion Poll confirmed our feelings about this topic.

Note that information on this page can change any moment as the program is still in full development. Therefore you should read this page as having a look in our kitchen on the current state of a new product.Items marked with are new since last update of this page.

REBEL10.5 What's New in the GUI?

  • Full Logfile support by one simple mouse click. For an example click HERE. The Logfile has 3 options:

    • Write analysis to the logfile of the current position (default setting).

    • Write all analysis to the logfile of the current session (using append). This may result in a very tall logfile, on the other hand every action is recorded. The logfile is overwritten every time you start REBEL.

    • Write all analysis to the logfile of the current session (using append). This function keeps ALL logfiles. Logfiles are simply numbered by date and an extension number. Examples: 99-05-22.001 , 99-05-22.002, 99-05-23.001 and so on.

    • You can switch between these options using the direct keyboard shortcuts SHIFT-F6 and SHIFT-F7

  • Option Club Player. REBEL so now and then deliberately will make a mistake. The range of mistakes can vary from minor positional mistakes to a material loss of 2 pawns.

  • Option Analyze game extended. If moves are marked with "??" (using the annotation symbol shortcut) REBEL will analyze those moves only. This will shorten the analyze process tremendously.

  • The new function is also supported for multiple game analysis if you have marked multiple games in the database.

    The new main variation

    • Main Variation extended from 7 to 24 plies.

    • Main Variation now in short and long notation depending on your preferred setting.

    • Using the setting INFO=SUPER (menu CONFIG) will store the main variation in the TEACHER WINDOW too to ensure the complete main variation (max. 24 plies) is shown in a good looking way. Click HERE to view.
  • The ELO level (set REBEL to your own strength) is further improved. Rebel now will limit its opening book if you set Rebel's elo to 2200 or below.

  • New features under consideration

    • EPD viewer. Direct access to EPD collections (PGN alike).

    • Database history. Easy swichting from one database to another. REBEL will remember the last 10 databases you have used. No more browsing on your hard disk just pick the database from the history list. The history will support REBEL, PGN and EPD databases.

    REBEL10.5 What's New in the BOOK?

    The new Jeroen Noomen book has been extended with another hand-typed 130 Kb (is 65,000 new moves) to update the REBEL10 book concerning the latest new opening theory.

    One of the main advantages of the standard REBEL book is that it contains a lot grandmaster analysis on critical positions of human theory.

    REBEL will play these grandmaster analysis too and therefore REBEL is even able to surprise the most experienced GM experts in opening theory since most of these lines are tried in GM tournaments.

    REBEL10.5 What's New in the EOC?

  • A brand-new Encyclopedia of Chess database will be created (most probably) based on 500,000 to 600,000 high quality games.

  • The EOC-USE settings ACTIVE and STRONG are improved and are now much more intelligent than the ones of REBEL10. The gained EOC bonus score is displayed in the logfile for each main-variation so you can exactly see to what intend the EOC database has guided REBEL to its moves played.

  • The EOC-USE setting BOOK is improved too. It's quite safe now to use the whole EOC database as one big book without loss of too much strength. The latter because a book plays moves at random due for reasons of variety.

  • REBEL10.5 What's New in the DATABASE?

    A brand-new DATABASE will be created (most probably) 500,000 to 600,000 high quality games.

    More info soon.

    REBEL10.5 What's New in the ENGINE?

    Starting point of the engine is the more positional based Rebel10.0b keeping the good things of Rebel10.0c. Various positional changes have been made to make REBEL a better positional player and analyze partner.

    The engine is now fully flexible and user configurable. It's expected REBEL (and the user) will profit a lot from that.

    You can now tune REBEL 10.5 in 3 different ways:
    • Tune the most important positional values of Rebel (range 1-500).
    • Tune the material values of Rebel (range 1-500).
    • Tune the search and/or extensions.
    All of this is done by a simple ENGINE text-file (kind of INI file) which you can modify to your own wishes. Have a look at REBEL10.5 default ENGINE.

    All you have to do is to change the scale (range) values. All default settings for REBEL 10.5 are 100. By modifying these 100 values you can increase or decrease the specific chess knowledge in REBEL10.5.

    To modify (or create new) engines (or personalities) you can use Rebel's build-in personality editor or use a special stand-alone program. Click on the pictures to view them in real size.

    The SEARCH options in more detail as we assume the rest of the ENGINE file is self-explaining:

    • Overnight Search is very useful for correspondence players or for people who often use a chess program for long analysis up to 24 hours or more. The problem with most chess programs (previous REBEL's included) is that after some time (15-20 minutes) the search kind of blocks and becomes slow as a snail due to a full hash table. The result is that a new main-variation can take ages.

      Overnight Search solves this problem and you may expect better results in the end. Overnight Search will limit several extensions to reasonable margins as Overnight Search assumes that tactics (if present) will be found anyway. As a result Overnight Search typically searches 3-4 plies deeper while you are sleeping. Also the hash table use by the program is tuned for this option.

    • Risky Search typically will speed-up the search with 15-20%. Risky Search takes a bit more risk than the default search and is almost without any negative side effect. You can safely set Rebel10.5 to this value.

    • Deep Search will look for deep tactics. REBEL10.5 most of the time will find a combination 1 ply sooner.

    • Deeper Search will look for deeper tactics. REBEL10.5 most of the time will find a combination 2 plies sooner.

    • Deepest Search will look for even more deep tactics. REBEL10.5 most of the time will find a combination 2-3 plies sooner.

    REBEL10.5 engine personalities

    Multiple ENGINE files (see above) can be created and loaded. These files are called PERSONALITIES. Within Rebel10.5 10 personalities are pre-programmed. From the menu OPTIONS you load the following personalities:
    • Garry Kasparov
    • Robert Fischer
    • Michael Tal
    • Anatoly Karpov
    • Vishy Anand
    • Judith Polgar
    • Strong Club Player
    • Average Club Player
    • Novice Player
    • Rebel10.5
    We will add some examples (including diagrams) later to prove it is possible to addapt the playing style of these great chess players with REBEL10.5 new engine concept.


    Every chess program is released with its "default settings" which according to the programmer are the best settings he is aware off. But are these "default settings" really the strongest ones? This is unlikely as chess (and programming chess) is much too complicated to say that for sure!

    The more likely truth is that there are maybe easy elo gains the programmer isn't aware off. The "Pilz" settings of Chessmaster are famous for that.

    REBEL10.5's new "flexible engine concept" allows easy and powerful tweaks (tuning) of the engine by the user and it is expected to get an elo improvement of 30-50 points by finding REBEL's ideal default settings.

    The challenge for you the end-user is to find REBEL's ideal default settings!
    • $1000 for the best improvement.
    • $500 for the second best improvement.
    • $250 for the third best improvement.
    More details at release time!


    REBEL10.5's new "flexible engine concept" allows easy and powerful tweaks (tuning) of the engine by the user. Here are some examples of what is possible with the new REBEL10.5:


    Multiple ENGINE files can be created and loaded. These files are called PERSONALITIES. Within Rebel 6 famous personalities are pre-programmed and can be loaded from the menu OPTIONS. Click on the above players to view some examples (including diagrams) and see that is possible to addapt the playing style of these great chess players with REBEL10.5 new engine concept.

    Last update July 30, 1999

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