Pro Deo 1.5

Pro Deo (version 1.5) approximately 2700 ELO - Size 4 Mb
  • Download Pro Deo 1.5
  • After the download open the archive with WINZIP and double click SETUP.
  • To run PRO DEO you will need to announce the engine first.
    • Under Chessbase this means: Engine -> New UCI engine -> Browse -> RebelUCI.exe
    • Under ChessPartner do: Extra -> Engine Import Wizard -> Winboard engines -> Install -> ProDeo.exe
    • Under ARENA do: Engines -> New Engine -> UCI -> RebelUCI.exe
  • ARENA is freeware and can be downloaded here.
What's all the fuss about?
  • Pro Deo 1.5 with EOC uses an EOC database as a source to guide the opening and middle game. The default EOC database is made from 6700 Pro Deo games gathered from various Internet sources played at a minimum level of 30 seconds average and made with Pro Deo Tools.

  • As such Pro Deo 1.5 knows which opening lines are good and bad and based on its history Pro Deo 1.5 adds a bonus or penalty to each move that has been played before by Pro Deo, a bonus if the history is positive, a penalty if the history of the game shows a negative score.

  • For example: based on the 1.d4 d5 position Pro Deo 1.5 with EOC will add an 0.54 bonus (see picture) to the move 2.c4 and play that move already at ply-2. Moves like 2.g3 and 2.Bg5 are discouraged by a penalty of -0.25 etc.

Older Versions

Pro Deo 1.4
Pro Deo 1.3
Pro Deo 1.2
Pro Deo 1.1
Pro Deo 1.0

Author Note

This new version does not contain any engine improvement (except a 5% faster compile) so if you are only interested in engine strength keep the old 1.2 version and don't upgrade.

Ed Schröder
Deventer, June 2007


Since the EOC approach is an open source engine programmers can easily add the algorithm to their own engine and add 20-30 elo points without too much of a hassle.

Just collect as many as possible reliable games from your engine (no blitz games), make an EOC database from it with Pro Deo Tools and for each root-move call the EOC database, see the documentation.


Other tries such as using a big fat EOC database with over 100 million positions made from a 3 million games database remained unsuccessful, the trick seems to be using the games your own engine played exclusively.
Copyright © 1984 - Ed Schröder
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