CheckChess: Cheat Detector

Lost to someone who played a little too well? CheckChess tells you whether the feeling holds up, using their whole game history, not just one game. HOW IT WORKS 1. Enter a Chess.com or Lichess username, or paste a PGN from an over-the-board game. 2. Stockfish analyses the games right on your phone. 3. You get a 0-100 suspicion score and a report that shows exactly where it comes from. CATCHES WHAT ONE GAME CAN'T Many cheaters only use an engine in some of their games. A single-game checker can't see that. CheckChess looks at a player's whole history and compares it with people of the same rating, so selective cheating shows up as a pattern. The score is built from move accuracy, how often the player matches the engine's first choice, average centipawn loss and move-time patterns, all measured against typical play at their rating, not against a grandmaster. WHAT YOU GET • Account scans: any Chess.com or Lichess username, scored from that player's public games. • OTB analysis: paste a PGN from a tournament or club game and get the same treatment. • Detailed reports: per-move accuracy, centipawn loss and engine-match rate, charted game by game, so you never have to take a number on faith. • Watchlist: keep an eye on suspicious accounts and get notified when they play again. • AI analyst (Premium): ask follow-up questions about any report and get answers grounded in that analysis. PRIVATE BY DESIGN The engine runs on your device. The engine pass never goes to a server, and a PGN you paste never leaves your phone to be evaluated. HONEST BY DESIGN A verdict on eight moves is worthless, so CheckChess does not give one. Short games, engine-vs-engine games and thin samples are excluded and reported as such. The score is a statistical signal, not proof. It exists to inform your own judgement, not to be used as a public accusation against anyone. FREE • 5 account scans and 3 PGN analyses a month • 1 watched account • Summary reports PREMIUM • Unlimited account scans and PGN analyses • Full reports: charts, flags, per-move breakdowns • AI analyst: 30 messages a week on Weekly, 1200 a year on Yearly • 10 watched accounts • PRO badge on your profile Premium is an auto-renewable subscription, available as a Weekly or a Yearly plan, billed through your App Store account. Cancel anytime in your App Store account settings. CheckChess is not affiliated with or endorsed by Chess.com or Lichess. Stockfish is used under the GNU GPL v3. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/