Hi Chris, thank you so much for this comment.
As you said, football is beautifully unpredictable. If we look at the Oxford predictions they say “Brazil vs Belgium” and none of them went over the semifinal (actually Belgium is out at the group stage!!!).
I believe that the 6 matches group stage is the biggest flaw of my model and also it doesn’t consider any information about the players and their skills/market value.
As I say in the first line, I would consider this as a fun model implementation rather than a realistic “artificial tipster”.