surely you through trial and error you can make a. good system for catching obvious cheating but be careful and of overestimating your common sense.
u guys said if someone makes weird moves like h4 h3 that don't seem to do much, high percentage of their moves match stockfish, or suddenly a low player makes a 7 move combo, then that's obvious that cheating.
thing is, I am by most accounts 850 to 950 at best, but all those things happen to me from time to time. sometimes, as Fischer says, the tactics just flow from the position. you don't know have to see where a combinationof is going through to have a hunch and follow it. and I make weird computer moves sometimes because... dun dun dun... i review my games with an engine and try to learn from that.
so be careful assuming a bad player is using an engine. sometimes they may just be making unsound guesses and getting lucky. you'd have to see what their other games are like, maybe they make those "computer moves" in other positions or start unsound combos just as often as their "amazing ones"
using a computer is not cheating
lol