I would have to do more research than I care to to prove it, but I'm pretty sure from my personal recollection that the 66% phenomenon ended after this change: https://www.reddit.com/r/announcements/comments/5gvd6b/score... -- assuming my memory is correct, that suggests it was an artifact of the anti-cheat techniques being used. (Not an intended one though, obviously, if you guys believed 66% was legit before the recalc.)