Luck/Turmoil versus Nothing.

[Finalgenesis]

I've also noticed that events clusters and tend to like certain provinces, often times I get events for the same province 50%+ of the time per turn over a year or so. I think it's easily observable, after two or so years holding 10+ province you should notice that certain province name pops up a lot more often, I usually end up memorizing where the province is base on the name for those that gets an event every other turn or so.