If anyone wants to listen to an example of a somewhat difficult quiz programme they could try Brain of Britain - a long running radio show on BBC Radio 4.
Likewise. I'm usually at least decent at general knowledge quizzes and was more than 20 questions into the episode I picked before I knew an answer 100%.
The episodes available in the US at the GP's link are all Semi-Finals and Finals. Could any regular listeners comment as to whether they tweak the difficulty for the tournament or if it's always such a relentlessly high bar?
https://www.bbc.co.uk/programmes/b00813s0
I don't know if it's geo-blocked, or if there's anything available for download. But they do have written questions too.