Consider a mobile chess app which allows to play correspondence chess.
Some apps, like this one, state that they'll punish someone (e.g. disable their account) if they discover that the person is cheating.
Is that really possible to reliably know if someone is cheating (e.g. uses a chess engine to decide on the next move)?
Are there any heuristics that can exist in the app that will calculate the probability that player is cheating?