I've had this going on for a while, not in each and every game though. I had a frenzy in multiple games and for some weird reason my first spree was on my 7th kill when I hadn't even died once. I've gone on to running riots where my first spree was a spree, second was a spree again which should have been a frenzy and then my running riot to be a frenzy. Why does this happen?