Not bad! Yeah, wouldn't be surprised if those are part of the detection algorithm.
I would take longer to detect a cheater who is a bit more sly and only cheats on 5% of moves or less (the odds that someone would match a particular engine 99% of the time its pretty much zero), but over time, yeah, this would work.
I suppose another way to put its is that it's difficult to detect this sort of cheating from a single game, but not difficult to detect it in 100 games.
I would take longer to detect a cheater who is a bit more sly and only cheats on 5% of moves or less (the odds that someone would match a particular engine 99% of the time its pretty much zero), but over time, yeah, this would work.
I suppose another way to put its is that it's difficult to detect this sort of cheating from a single game, but not difficult to detect it in 100 games.