CommentStreams:691e32ddeaf586e10015eb6a41186382

I collected more data and now my estimates for the chest rarity chances are:

common 72.5%

rare 19%

epic 6%

legendary 2.5%

One could hypothesize that it may be set up to be declining by a factor of 3, 27:9:3:1 which would give 67.5%, 22.5%, 7.5%, 2.5% but thus far my numbers above are somewhat different from this theory.