About Chessy

Chessy is a solo-built product. Every lesson is written and verified by code — not generated wholesale by an LLM — and grounded in Stockfish evaluations and Lichess statistics from hundreds of millions of real games.

Stockfish — the world's strongest open-source chess engine, rated 3500+. Every position evaluation (centipawn score and best continuation) on Chessy is computed directly by Stockfish at depth 12–16, not estimated or copied from another source.

Lichess — the largest open chess database. Win rates, game counts and top continuations come from Lichess's opening explorer API, covering hundreds of millions of rated games across all time controls.

Every lesson includes a browser-based drill: you play the opening moves against an adaptive Stockfish engine that adjusts to your estimated level. No downloads, no signup, no cost — the engine runs entirely in your browser.

Free accounts unlock move-by-move AI coaching that explains every inaccuracy as you play, plus a personal Telegram coach that reviews your real games from Chess.com.

Each fact on a lesson page — win rate, game count, Stockfish evaluation, ECO code — is pulled from the source at page-generation time and embedded directly. There is no editorial padding or invented claims; if a number appears, it comes from Lichess or Stockfish.

AI coaching text is grounded: the coach sees the engine's actual verdict on each move before commenting, which prevents the invented threat lines and ownership confusion common in other AI chess tools.