Key Fragment Drop Rate?

I've gotten 1 total fragment in about 30 wins, and that's after it was supposed to have reset.

I think it's based on your/team performance. I've had key fragments drop in succession, and then long dry spells in between.

I've obtained every crate thus far and I'm still sitting on four more with one key fragment.

I havent been playing bad either. Been working on my mastery 6 and 7's on my main Jungle assassins. Im getting S's and tokens but no fragments. Is it like a roll of the dice on whether or not someone gets one when an S is obtained?

this is pretty normal, the first few keys frags are very easily obtainable after the rest, and progressively get harder and harder to obtain every fragment you get. remember key frag drop rate reset every 4 weeks...