That's cool. I wish I had a headmaster who can prepare me for an interview in which I ended up discussing project euler questions, prolog, how jpeg works and how the way humans sort relate to how computers sort.

In maths interview, they give you an open question of some sort and want you to have a go at it. It's generally trivial and obscure so you cannot know the answer. How do you prepare for that?

It might work in history but simply not in STEM subjects.

Err its more the soft aspects and confidence and knowing the unwritten rules they are coaching - you no longer need basic Latin to go to Oxford or Cambridge.