How to tell if someone is CHEATING at chess.com

Has an easy oppenent picked up 1000 rating points, i.e. was using an engine or had an “angel” looking over his shoulder suggesting moves?

There are three main indications of cheating that easily come to mind.

1. It is easiest to determine if you have an indication of their previous play and the best indication is a rating. If someone is rated low and plays a perfect grand master game with no mistakes. A low rated chess player will not be playing like a master in a couple of weeks. If you are rated at 500 and winning against players 1000+ higher on chess.com, that is highly suspicious.

2. The second indication of cheating is easier to identify and does not require any context and history. If the game is entered into an engine with analysis, and the opponents choice has little deviation from the top recommended moves, it leaves one to wonder. Human players can find the computer best move, and certainly the stronger the player, the closer it will often be. But continually hitting the computer recommended best move is a clue. Especially telling but harder to define are nuisance moves that have a computer sense without any threat or underlying reason for the move. On chess.com if someone us playing with 99% accuracy in their last few games, that is highly suspicious.

3. Thirdly would be how professors detect plagarism in papers - by detecting a sudden change. In chess, this is extremely difficult to define, but a sudden change in play style or play strength may indicate cheating. On chess.com when your computer percentage moves from 13.2 to 99.3 when a game is analized in a couple of days and your rating is 500 is very suspicious.

CHEATING IS NOT TOLERATED ON chess.com.