Play this position against the computer
白と黒の配置を選んで（表示中のままでも可）コンピューターと対局しましょう。計算はブラウザ内で行われ、どこにも送信されません。
番号は0〜959。両者が同じ番号なら通常の対局、違う番号ならそれぞれが自分の配置で始めます。
バランス計算済み。 モロゾフ・バランス指数：100 中 93 — クラス A — 最もバランスが良い。
エンジン評価：白から見て +11 センチポーン（バンド S — わずかな優勢）。 深い再計算で確認済み。
How strong is it, honestly
Two opponents answer here, and the page always says which one. The real one is Stockfish 19 Lite compiled to WebAssembly — the same engine that analyses games at the top level, running in your browser. You choose its strength next to the board, from about 800 to 2000, so that a beginner gets a game rather than a demolition.
Stockfish is 1.2 MB over the wire, so it loads when a game begins: here, with the first move (yours or, if you play Black, the computer's); on the home page the game starts by itself as soon as the page loads, so there it loads at once. Until it is ready, a small engine built into the site answers: it is far weaker, but it replies instantly. The rules are the same for both and are not theirs: moves, Chess960 castling, check and the end of the game come from the rules library that drives the board here and the Android app.
Everything is computed in your browser. No position and no move leaves this page.
Stockfish is free software under the GPLv3; its source is at github.com/official-stockfish/Stockfish, the WebAssembly build at github.com/nmrugg/stockfish.js. CH960 is GPLv3 as well.
Where to go next
Encyclopedia of balanced pairs
For a real opponent — people or a full engine with mentors — there is the Android app.ブラウザでも Android アプリでも。インストール不要 · 無料・広告なし