🏆 Matchmaker

The tiny correct matchmaking rating kit. Elo for head-to-head, Glicko-2 for rating periods — drop it in, stop reimplementing it badly.

1 · Elo playground

2 · Matchmaking

3 · Rating explainer

4 · Tap a rating

Elo: expected score = 1 / (1 + 10^{(Rb−Ra)/400}); updates are zero-sum. Glicko-2 (Mark Glickman) adds a ratings deviation (RD) — how sure the system is — plus volatility, updated once per rating period. Full algorithm in the library; see README for the citation. 100% local — no network, no server.