Belofte - About

This file references belofte versions 0.9.


Belofte is a promising chess program. Belofte is a Flemish word that can be translated as 'a Promise' or 'someone with potential'. In this context, the latter is the intended meaning. The most correct translation would be 'A promising chess program'. It is pronounced as 'b-euh-loft-euh'.

Please refer to License, About, Manual or Todo. More information on its authors can be found in the license terms.

The chess program comes without user interface but is compatible with xboard. This means, it can be used as a plug-in for the majority of all commercial and free chess programs. At this moment, it has been tested on Mac OS X. There is nothing that stops it from being used on any version of Windows or UNIX or Linux, if one would like to make such a version. The current strength of Belofte is about 1200 elo at in in Lightning and 750 in Blitz. Version 0.2.8 has 751 on GURL. Version 0.9.0 has 692 on CCRL. Version 0.9.3 has 989 on CCRL. Version 0.9.12 gains at least 200 elo.

Using Belofte

Please refer to the manual for more detailed instructions. For a quick introduction, please read the file.

Mac OS

On Mac OS X (before Tiger 10.0, 10.1, 10.2, 10.3)
Minimum requirement is a G3 with 32 MB ram plus the requirements of X11.
On Mac OS X (10.4/Tiger/PPC)
Version 0.2 till 0.2.8. This software has not been tested on this platform. If you have this platform available and want to co-operate, please mention so that the port can be done.
On Mac OS X Intel (10.5/x86)
Universal binary available. Same as PPC version.
On Mac OS X (10.8, 10.9, 10.10, 10.11)
Intel x86_64 available.
On Mac OS X (10.12 and higher)
Not yet available. Contributions wanted.


Windows 32 bit: NT, 95, 98, Me, 2000, XP, Vista, 7, 8, 8.1, 10
Version 0.2 till 0.2.8. Version 0.9.8 and higher are available.
Windows 64 bit
Please run 32 bit version. Version 0.9.3 is available as a custom 64 bit build.
Windows 3.11
Version 0.2 till 0.2.8. Higher versions have not been tested. Make sure you have Win 32 installed.
Windows CE, Pocket PC, Windows Mobile
As of 0.9.0, development has ceased on these platforms.


Linux x86 (32 bit)
Version 0.2 till 0.2.8. Version 0.9.13 and higher available.
Linux x86_64 (64 bit)
Version 0.9.0 and higher available.
Linux PPC
FAT binary version under development.
It can be played against on when the application is on-line. You will require Winboard as an interface. You can also select one of the other interfaces that are available.

Other platforms


Binary version 0.2 is available.


Binary version 0.2 is available.


No plans for development at this moment.


In the pipeline.


No plans for development at this moment.

License terms

This software and its source code falls under the GNU GPL Version 2, June 1991 with some special provisions. Please refer to the license document for full details.

Other information

Rating lists
Version 0.2.8: position 1207
Version 0.9.3: position 631
Version 0.9.0: position 643

From the MacChess site:

    Belofte is a self-written chess program available on Mac OS X and on
    Linux i386. It works with XBoard or from the command line.

    It also plays on under the same name. You can meet it
    there during weekdays in between 20.00 CET and 06.00 CET.

    The main concept behind 'Belofte' is not to be yet another chess
    program but to change some fundamentals in chess programs. Most chess
    programs work by selecting the best move according to evaluation and
    search. 'Belofte' is different in that. It will select amongst
    one of the good moves according to a certain desire. It changes
    fundamentally from the traditional minimax algorithms; it does not
    retain the best move in a certain position, but a series of plausible
    moves in a position.

    For that, it will analyse the games of the opponent to see what moves
    he/she will play and uses these moves in its analysis.

    I do not throw away all chess development concepts:

    What is implemented is:
    •  Alpha-beta
    •  Quiescence
    •  Opening books

    What will be implemented in the future is:
    •  Iterative deepening
    •  Transposition tables
    •  Endgame tablebases
    •  en-passant moves
    •  analysis mode

Finger it at

Finger of Belofte(C):

          rating    RD win loss draw total best
 Blitz       742  50.9  11   70    0    81  827 (30-Nov-2004)
 Lightning  1164 305.0   0    2    0     2

 Total time online: 14 hrs, 11 mins
 % of life online: 13.0 (since Sun Nov 28, 01:43 CET 2004)

 Timeseal : Off

 1: I am a computer, running on a Dual G4 1.25 Ghz
 2: I am not strong though, rated around 700 elo but improving
 3: You can find more on
 4: I do not have opening books, no endgame knowledge, no nothing....
 5: I play regular chess. Other variants will be added later.
 6: I will not play against abusers.... and only rated games. For now.


Language Native translation Name of application.
English English Belofte - A promising chess program
Flemish / Dutch Vlaams / Nederlands Belofte schaak
French Français Promesse échecs
German Deutsch Schach
Spanish Español Ajedrez
Russian Русский Шахматьі

Beware of Elo levels

There are as many elo levels as peer groups. Elo levels can be compared to IQ. They give a relative indication how persons compare to each other but they cannot be used to compare a person of group A to a person of group B. FIDE elo at the 1900 range is comparable to USCF in the 2000 range, and FIDE 2500 is comparable to USCF 2650. The score obtained for a program should more or less be the average of all different tests, but is no absolute indication. For each test set, the elo level for a 50% and 100% score is given, together with the standard deviation. When scoring less than 50%, the results should no longer be representative.

Evolution of strength

The version has undergone some enhancements over the different versions. Some were not always correct. For a history of the different versions, and their reflection on the ELO obtained, please consult the table below.
Version Released Elo Comments
0.1 680 ?? First version
0.2 Ports to Solaris and HPUX
0.2.2 ??? Internal development version
0.2.4 ??? Internal development version
0.2.5 1038 ?? Internal development version
0.2.6 1190 ?? Opening book implemented. Rating obtained after 6600 games. Top rating 1294.
0.2.7 19/03/2005 1130 ?? Mac OS X version. Saving multiple times same game resolved. Slight change in evaluation function. Windows version available. Linux version available.
0.2.8 17/05/2005 950
751 on GURL-2
742 in FreeChess Blitz
Added opening book colour transposition and better balancing of good moves in opening book. Better handling of shorter games. Correction of castling information. Adding partial comments for autodoc. Documentation available. License conditions added. Rename of binary book and taking into account Intel Mac for opening books.
0.3.0 after 17/5/2005 not rated Conversion to Universal binary, a lot of optimizing. But still not finished. It plays from time to time on the internet and while under development. First conversion to cpp
0.4.0 till 0.6.2 after 17/5/2005 not rated Implementation of multi-threading and multi-algorithm. Development on Win32 platform.
0.9.0 06/06/2017 692 Continuation of 0.2.8 branch, port to Linux 64 bit. Change in license conditions, available on Git. The 0.9.0 branch is the temporay version of 0.9.0 containing the big part of work. It has been merged in the master branch and tagged on final release.
0.9.1 and 0.9.2 24/07/2017 1100 (estimated) Instead of fixed depth based on available time, respect time levels. Recognises 3 fold repetition. Correction of some illegal moves. Multi-threaded approach. Different threads: UI, timeobserver, search, pondering. Updates on evaluation function. Huge increase in strength.
0.9.3 12/07/2018 989 Standard build does not compile UCI specific commands. Multi-threading fixed on linux build. Available on Win64 and Linux64.
0.9.6 till 0.9.8 10/12/2019 1100 (estimated) Standard build does not compile UCI specific commands. Other builds not tested. Available on Win32 and Linux64.
0.9.10 06/02/2020 1200 (estimated) Xboard protocol only. Available on Win32 and Linux64.
0.9.12 12/02/2020 1300 (estimated) Quiescent search fixed. Xboard protocol only. Available on Win32 and Linux64.
0.9.13 till 0.9.14 13/02/2020 1300 (estimated) Xboard and UCI protocol. Available on Win32, Linux32 and Linux64.