Engineering · Chess
Chess Tournament Tracker
A live grandmaster tournament tracker embedded in this site — auto-discovers the current top Lichess Broadcast, shows standings and pairings, and lets you replay completed games move-by-move.
The tracker pulls data from the Lichess Broadcasts API — the same feed that powers coverage of events like the Candidates and Norway Chess. No API key required; it polls every 60 seconds and backs off automatically if the rate limit gets tight.
What's here
The current phase shows the active tournament name and round. Standings, pairings, and game replay are coming in subsequent slices — tracked as open issues on GitHub.
How it's built
Pure data layer. BroadcastService is a dependency-free async module: it fetches, parses rate-limit headers, and returns a structured result. The React layer never calls fetch directly. This keeps the polling logic fully unit-testable with a mocked fetch.
useReducer for state. All state lives in a single useReducer at the top of the component tree — no external store. The reducer is a plain (state, action) → state function, the same pattern as the Vienna trainer, and equally straightforward to test in isolation.
Rate-limit back-off. Every response carries an X-RateLimit-Remaining header. When it drops below 10, the polling interval switches from 60 seconds to 5 minutes automatically — no manual configuration needed.