Prepare like a professional.

A speed-first chess database: 2.5M tournament games behind a transposition-aware opening explorer, opponent preparation, and a full-strength engine that runs entirely in your browser.

2.5M
games
0
opening positions
111,685
players
weekly
days between updates

Opening explorer

Transposition-aware statistics for every position: frequency, results, ratings, and the strongest games — answered in a single index read.

On-device engine

Stockfish 18 runs multithreaded in your browser. Full-strength NNUE if you want it. Nothing you analyse ever leaves your machine.

Opponent preparation

Walk any player's repertoire on the board. Lines they play often but score badly are flagged as preparation targets.

Full-game analysis

One click evaluates every move: eval graph, per-player accuracy, and blunder badges — computed locally, free at any scale.

Novelty detection

Every game page finds the exact move where it left known theory, with the size of the book before it.

Players & head-to-head

Rating histories, repertoire summaries, and lifetime head-to-head records between any two players.

Explore an opening

All openings →