Key fragment drop rate resets every 30 days. How about a High/Moderate/Low rate indicator?
For anyone confused about the frequency of Key Fragment drops, the drop rate is a curve rather than linear, meaning you'll get them frequently at first but quickly earn very few afterwards.
How about add a Key fragment drop rate indicator on your profile page where the Chest/reroll/first win info is. It can simply say;
Key Fragment drop chance: High/Moderate/Low
Once you hit low you know farming them is futile, and when it hits high again you know the chance has reset. Mousing over it will explain.
######For more information on Hextech Loot and eligibility, read these articles; https://support.riotgames.com/hc/en-us/articles/207884233-Hextech-Crafting-Guide ######http://boards.na.leagueoflegends.com/en/c/player-behavior-moderation/57wOcrmh-if-you-are-ineligible-for-hextech-loot-read-here-for-info-on-becoming-eligible-again