A growing reference list and documentation project for computer chess engines.
One of the main targets is keeping track of the latest engine releases. This also includes Elo ratings for three different Time Controls that are meant to be representative - Short, Long and Very Long. These ratings are calculated in one big, endless tournament that started in 2024.09.18. Engines are playing direct neighbour engines in the rating table until they have found their place, then they are playing two engines up and down, and so on. Note that the several TCs are all playing the same tournament to calibrate them against each other, so we can directly compare them and see, how the engines perform over the various TCs.
The development of an engine over time is displayed here, e.g.: Stockfish or Raphael
A complete list of engines can be found here: CCI Ratings per Release or CCI Ratings per TC.
In the effort to improve the (external) calibration, I made experiments with Lichess Bots. These experiments are currently halted - my calibration efforts are not yet finished, but consider this an insight of the direction I'm thinking about calibration.
The Computer Chess Index (CCI) is an open and continuously evolving attempt
to document, organize, and preserve information about computer chess engines —
their origins, versions, and development over time.
The goal is to provide a reliable reference structure for anyone interested in
the technical and historical landscape of computer chess.
This repository begins as a personal initiative,
built around data collection, normalization routines, and transparent reporting.
- Collecting and verifying public information on known chess engines
- Building a clean, consistent data model for long-term use
- Publishing regular update reports and basic metadata exports
- Exploring automated data imports and validation workflows
| Folder | Purpose |
|---|---|
/Releases/ |
YYYY.MM Overview of that months releases |
/lists/ |
complete lists of engines and evaluations |
/engines/ |
Engine overviews |
/docs/ |
General documentation and background notes |
"With cautious skill, tap by tap — a small chip of rock, and no more, perhaps, in a whole anxious day — so could we work, and as the years went by we should open up new ways, and display far chambers that are still dark, glimpsed only as a void beyond fissures in the rock."
If you’d like to contribute by sharing verified information,
suggesting structure improvements, or testing data workflows,
contributions and feedback are welcome.
This project is maintained voluntarily. Support channels like GitHub Sponsors are not set up yet. If you wish to support, I'll happily activate support channels.
Metadata and documentation are released under CC BY-SA 4.0.
All referenced binaries or original works remain property of their respective authors.
This is not an official archive or institution — just a careful,
structured, and long-term effort to make sense of the evolving field of computer chess.
“Every engine is a reflection of its time.”
Leave me a note in discussions
or
mail to: computer-chess-index (at) proton.me