A chess analysis tool that combines game-tree search with natural language generation to help players understand their own decision-making biases.
CheckPause evaluates every move with a local Stockfish engine, then lets any OpenAI-compatible model explain the engine data in plain language, alongside a clickable move list, a custom-drawn board, performance ratings, and a personal growth profile.
- PySide6 desktop app: the board on the left, with Import / Analysis / Statistics tabs, in Chinese or English.
- Local engine analysis: Stockfish scores every move with progress and stop support; a Polyglot opening book detects book moves and skips engine work.
- AI explanations: streamed answers based on engine data, with follow-up questions like a real coach; works with DeepSeek, OpenAI, OpenRouter, and local models.
- Clickable move list: jump to any position and highlight the current ply; the board also shows engine best-move arrows and can be flipped.
- Play against the computer: the Play module takes on Stockfish with click-to-move, White/Black, a 100–3000 rating slider (1320 and above calibrated by the engine's Elo limiter), common time controls (1+0 through 30+0, with increments or unlimited), selectable openings and endgames, undo, resign, promotion picking, and move review — plus one-click send to analysis. Setup pickers lock once a game is under way and unlock on New game.
- Puzzle training: a Puzzles module between Play and Analysis ships with a Lichess sample and accepts your own open collections (Lichess CSV, FEN-based PGN), with correct/wrong feedback, hints, and rating/theme display. A Favorites collection gathers the puzzles you star or miss for later review, and large collections are read lazily.
- Performance ratings and profile: five tiers (Optimal / Precise / Competent / Steady / Volatile) plus per-game accuracy history on the Statistics tab.
- Personalization: 10 Lichess piece sets, 6 board themes, and light/dark modes, applied instantly and saved.
- Privacy first: your games and API keys stay on your machine; analysis never depends on the cloud.
- Get
CheckPause_Setup_1.8.0.exefrom the Download section at the end of this file. - Run the installer and follow the prompts — no administrator rights needed, and a desktop shortcut is optional.
- Launch CheckPause from the desktop or Start Menu; first launch asks for a username and interface language.
- Open Settings → API settings... and enter an API key (DeepSeek by default; any OpenAI-compatible endpoint works).
- Paste or open a PGN on the Import tab, click Analyze, then ask questions on the Analysis tab.
Analysis and board features work without an API key; only AI chat needs one.
- Download the
.dmgfor your chip from the Releases page (M-seriesfor Apple Silicon,Intelfor Intel Macs). - Open the
.dmgand drag CheckPause into Applications. - The build is unsigned and not notarized. On first launch, right-click the icon → Open, or allow it under System Settings → Privacy & Security → Open Anyway.
- From there the steps match Windows (set an API key, import a PGN, start analysis).
- Settings → API settings... configures the API key, base URL, and model name; defaults to
https://api.deepseek.com+deepseek-flash, and blank fields fall back to those defaults. - User data lives in
%APPDATA%\CheckPause\on Windows and~/Library/Application Support/CheckPause/on macOS:profile.json(username, language, theme, appearance, history) andsettings.json(API config); legacy profiles migrate automatically.
- Pieces come from Lichess open-source piece sets (cburnett, merida, chessnut, fantasy, spatial, celtic, kiwen-suwi, rhosgfx, totoy, mpchess), each owned by its author under GPLv2+ / Apache-2.0 / MIT / CC BY / CC0 licenses.
- Engine: Stockfish (GPLv3); the opening book is compiled from public opening lines.
- The installer is built with Inno Setup and uses its official Simplified Chinese language file (
installer/languages/ChineseSimplified.isl, maintained by Zhenghan Yang). - License: CheckPause is proprietary software — Copyright (C) 2026 CometZZZ, all rights reserved. See LICENSE. Versions up to and including v1.6.1 remain available under the GPLv3 they were published with. Bundled components keep their own terms: Stockfish is GPLv3 (source available at https://stockfishchess.org/download/), and the piece sets keep the licenses listed above.
Latest: CheckPause v1.8.0 (Windows x64)
- 🚀 Fast mirror (recommended in China): CheckPause_Setup_1.8.0.exe — the same file served from a host that is reachable without the usual throttling, usually done in well under a minute
- 📦 Download from GitHub (114.7 MB — ships with Stockfish, the opening book, piece assets, and a curated Lichess puzzle set)
- SHA-256:
978609890A2650B934DF66F7C7B1947BF6EF51327F6ABD3A5B4E48200C12B804(both links serve the identical file) - Run the installer, then launch CheckPause from the desktop or Start Menu. The build is unsigned; if SmartScreen appears, choose More info → Run anyway.
Latest: CheckPause v1.8.0 (macOS)
- 🚀 Fast mirror (recommended in China): M-series (129.8 MB) · Intel (55.9 MB)
- 📦 Download from GitHub (both
.dmgfiles on the release page) - SHA-256: arm64
AFABF274E670F03925D0B03128E4F0A9C1574FEA7265640FA6E953F780DFE5B8, IntelFC9159043A626BBB8285674F5B99A956651D89CD4E74C44D1EF3C77A639A1A49 - Open the
.dmg, drag CheckPause into Applications, then right-click the icon → Open the first time (the build is unsigned and not notarized). - All releases: https://github.com/Comet-zzz/CheckPause/releases