They are intentionally opaque but I believe chesscom is using some browser tracking like checking if you’re tabbing out as a form of rudimentary anti cheat, and

They are intentionally opaque but I believe chesscom is using some browser tracking like checking if you’re tabbing out as a form of rudimentary anti cheat, and they can detect things like ban evasion and players using an alt. For the most part they’re working off public information though.