PSA: Articuno atop every gym, timer counts down from 3 hours.
Answers
I can confirm this, all articuno raid with 3 hour windows
The CP is down to around 29K, time to battle 180
Too bad no partly cloudy only sunny here
Try to duo it, and failed. In partly cloudy it is stil possible
Still have to use 2 golem in my little acc, and 3 bellow lv 30 Tyra SD/SE in my main account
In the border of win or loose if max out all 12 counter, but i don't have CTM and not enough Stardust so i cant test it..
Edit: my mistake, it is 180 second intead of 200.
Law of small numbers.
With a 5% chance for a shiny, if someone does 10 raids, they have about a 40% chance of getting one or more shines, and about 60% to get none. Of those who get one, 37% of them will get more than 1.
Chance of getting exactly 0 shiny in 10 raids = 40.1%
Chance of getting exactly 1 shiny in 10 raids = 31.5%
Chance of getting exactly 2 shiny in 10 raids = 7.5%
Chance of getting exactly 3 shiny in 10 raids = 1.0%
General formula for n raids is p(sh) = (0.05)^sh * (0.95)^(n-sh) * [n choose sh]
Your friend was unlucky, he or she had a 72.2% chance of getting at least one shiny in 25 raids.
From Thailand, some thoughts from our Articuno day today:
1) every imaginable gym did indeed have a 3 hour articuno so it was easy to do all 5 raids with a single 1 hour magic egg
2) I had a raiding team of 8 people (thus 12-15 accounts) and the shiny rate was not high ... only 2 trainers got shinys despite 5-6 raids each. Lets say 2 shinies out of 60 raids.
3) catch rate seemed higher than normal, no data to back that.
4) you can do 6 maybe 7 free raids if you keep your free pass from Friday.
5) you automatically get every free pass even if your bag is full, thus no need to worry about freeing item space, only Mon space
6) IVs seemed very good, my raid team had many 96 and 98%
I did 7 Articuno raids and caught them all. My level 40 got its first 100% and it came with Ice Beam, which I like. Took 380 legendary raids to get my first 100%.
Did another account today for 6 of the Artis and that got 2 shiny. Same deal with Kyogre, my level 40 was 0/27 on shiny. That level 35 was 2/10 on the shiny hunt. RNG is very tangible in my household.