Ajaxmoor is working with lots of statistics I believe. And champions league quali just started. Many times have never played against each other or their national leagues haven't started. So not much data to check and analyse.
Team performance, strength at home and away, goals per game, goals in first half and second half, performance in direct clashes and many many more.
So he is looking for probabilities to make the right clue/guess.
I like his method.