We are launching the VeryChess League, a series of chess engine tournaments dedicated specifically to engines available for macOS on ARM64 (Apple Silicon).
The goal of the VeryChess League is to bring together chess engines that can run natively on modern Apple Silicon Macs, compare their playing strength under identical conditions, track their development over time, and determine the strongest chess engines available for the macOS ARM64 platform.
Unlike a single standalone tournament, the VeryChess League is designed as a continuous competition. Engines can improve, new versions can be released, and their position in the league system can change according to their tournament results.
Initial Qualification
The VeryChess League will begin with a large Qualification Tournament involving all eligible chess engines available to us.
The purpose of this tournament is to establish the initial ranking of the engines by playing strength and divide them into leagues.
Each league will contain 15 chess engines:
- League 1 — the 15 strongest engines;
- League 2 — the next 15 engines;
- League 3 — the next 15 engines;
- and so on, depending on the total number of participating engines.
The qualification tournament therefore serves as the starting point for the entire VeryChess League system.
Engine Versions
Only one version of each chess engine may participate in the league system at any given time.
When a new version of an engine is released and accepted for participation, it replaces the previous version in its current league position rather than entering the competition as a separate engine.
From that point onward, the new version competes for the engine's position in the ranking. Depending on its performance in subsequent tournaments, the engine may move higher in the standings, earn promotion to a stronger league, or be relegated to a lower league.
This allows the VeryChess League to track not only the relative strength of different chess engines, but also their development over time.
League Tournament System
Each VeryChess League tournament series always starts with the strongest league and then proceeds downward:
League 1 → League 2 → League 3 → …
This order is important because the result of each higher league determines which engine will have to defend its position against competitors from the league immediately below.
League 1
The League 1 tournament consists of the 15 engines currently assigned to League 1.
After the tournament, the engine finishing in last place becomes the relegation candidate and participates in the subsequent League 2 tournament.
League 2 and Below
Every tournament below League 1 therefore contains 16 engines:
- 15 engines belonging to that league;
- the last-place engine from the league immediately above.
For example, the League 2 tournament consists of the 15 League 2 engines plus the engine that finished last in League 1.
The same system continues further down the league structure.
Promotion and Relegation
The visiting engine from the higher league must prove that it is still stronger than every engine in the league below.
To retain its place in the higher league, it must win the lower-league tournament.
If the higher-league engine finishes first, no promotion or relegation takes place between those two leagues.
If another engine wins the tournament, the positions are exchanged:
- the tournament winner is promoted to the league above;
- the visiting higher-league engine is relegated to the lower league.
This creates a direct competitive mechanism for moving between leagues: an engine cannot enter a stronger league simply by accumulating points over time — it must demonstrate that it deserves the place through tournament play.
Tournament Conditions
All VeryChess League tournaments are conducted under standardized conditions to make the results as comparable as possible.
| Platform | macOS on ARM64 architecture (Apple Silicon) |
|---|---|
| Tournament software | BanksiaGUI |
| Tournament format | Round-robin, four cycles |
| Engine configuration | 1 CPU thread per engine; 256 MB hash table; engine-specific opening books disabled |
| Openings | A common opening suite for all participants |
A common opening suite is used for all participants to provide varied and reproducible starting positions while preventing engines from gaining an advantage from their own opening books.
The same general tournament conditions are used throughout the VeryChess League series so that results from different tournaments remain meaningful and comparable.
The Goal
The VeryChess League is intended to become a continuously evolving ranking of chess engines for macOS ARM64.
Rather than producing a single snapshot of engine strength, the league system allows us to follow the ecosystem over time: new engines can appear, existing engines can improve, new versions can challenge established competitors, and engines can move between leagues according to their actual tournament performance.
Ultimately, the project aims to answer a simple question:
What are the strongest chess engines you can run on a modern Apple Silicon Mac?
The VeryChess League will try to find out — game by game, tournament by tournament.