"It's 20 hours grinding for 90% chance of a shiny Buneary at 150 spawns per hour in PC weather."

#PokemonGO: I just thought that after the Scyther shiny release and the reception to it here i'd congratulate Niantic on returning to a spawn/shiny rate combination that makes it enticing enough to hunt.From a relatively small sample of 168 spawns recorded, 58 were Buneary. Now this was during Partly Cloudy so this is likely boosted but anecdotally the spawns seemed ok earlier in Cloudy also. This translates to 34.5% of spawns potentially being the new shiny.This means that to have a 90% likelihood of encountering a shiny Buneary at the standard 1:450 wild rates it's..49 hours at a trip stop37 hours at a quad stop20 hours at a fairly reasonable 150 spawns per hour grinding rate (34.5% - 52 - of which are Buneary)Apparently I need to point out that this doesn't change the odds of any one shiny encounter although I would have thought that assumed in the conversation. Basically, if you haven't encountered a shiny after 20 hours of grinding 150 spawns an hour (~52 Buneary per hour) The very next Buneary you check is still 1:450.This is a measure of likely effort to get a feel for the numbers. After 20 hours without encountering a shiny you can grind for another 20 hours to bring it up to 99% likelihood.You can basically set a target for 1035 checks on each new shiny released and be ok that 10% of the time, on average, over the long run, you miss out (although of course with RNG you might get 3 Caterpie in it's 1035 and then 0 Buneary, 0 Wailer and 0 Zizagoon in theirs and be 1 from 4).Basically you calculate the grind time to see if it's realistic to get your hopes up and compare. For example, Scyther was about 200 hours of grinding for a 90% likelihood. It was too high to get excited about. Buneary at 20 hours is low enough that you've got a decent shot at making it happen. Calculating it like this changes it from "But there are hardly any Scyther!" to a more concrete "Scyther was 10 times harder to grind than Buneary" or "Do I have 4 hours per day for the next 5 days to have a good shot at a Buneary and is that worth my time?" or "I'm going to focus on grinding dust and lower my total spawns per hour to a communsurate level because I'm going to be playing 30 hours in the next 5 days"Again this is likely longer during non boosted weather but the numbers are back in the humanly possible range given there are 127 hours left of the event.edited to make it clear I'm using the 1:450 standard wild rate and to make it clear I'm not claiming odds are changing via /r/TheSilphRoad http://bit.ly/2vgN9PT