Magic Tricks

Reading the title and the blurb and seeing the demo, I was hoping that John had invented the perfect impromptu trick we all dream of. Just one prediction that was always convincingly right whichever of eight choices were made. Dream on! Sorry but, for me the outcome here is more likely to be embarrassing than magical.
John has a great reputation for card magic, which I am only mildly interested in, so learning that he was using his creative skills in another field got me quite excited.
I can think of ways to tighten this up considerably but I cannot say much more without revealing the secret of Miracle Method.