Mega Event Shiny Rates

Mega Evolution has finally come to the world of Pokémon GO, and with it a variety of new events. The current stars of the show are the new Mega Raid Bosses which can provide trainers with various amounts of Mega Energy depending on how quickly the bosses are defeated. As an extra special treat, after besting the Mega Raid Boss forms of the Kanto Starters, travelers may encounter a shiny Venusaur, Charizard, or Blastoise as a reward!

Currently, we are in the second stage of the Mega September event which is focusing on Mega Beedrill. This stage features a swarm of wild bug Pokémon, including the Five Star Pokémon Ledyba which can now be found in its shiny coloration. Our researchers, ever up for a challenge, decided to take on some super-strong Mega Pokémon raids, and also went hunting for a chance to encounter the special colored Ledyba. Let’s see what they found!

Mega Data

Silph Road Researchers were able to encounter 962 Kanto starters after defeating Mega Pokémon Raids, and found 21 shiny variations! This gives us an observed 95% confidence interval around the shiny rate of:

1/31 – 1/74

As no other previously observed shiny rate falls inside the confidence interval, suspicion must fall heavily on the Permaboosted rate of around 1 in 60 for Mega Raids.

Researchers have not collected enough data to draw strong conclusions about the shiny rates of individual species, and there is not significant evidence to conclude that they use different rates.

Species Raids Completed Shinies
235 4
485 9
242 8

Observant travelers will note that researchers have been particularly lucky after their Mega Blastoise Raids. However, the lower limit of the 95% confidence interval around the shiny rate stretches up to 1 in 69, suggesting that researchers have simply been lucky, and that the shiny rate of Blastoise matches that of Venusaur and Charizard. Our researchers will continue collecting data in order to investigate this observation further.


When it comes to the Pokémon Ledyba, researchers found 4,028 with 9 of those being shiny. These data suggest that Ledyba is using a shiny rate of:

Base Shiny Rate
(~1 in 500, 88% certainty)¹

While the confidence interval is still wide (1 in 267 – 1 in 1,022), there are no other previously used shiny rates that fall within the confidence interval. This suggests that Ledyba is using the standard, unboosted shiny rate that applies to most species most of the time.

Mega September 2020 isn’t over just yet. We still have another stage of the event coming up next week! Until then, stay safe, travelers.


Article by PhoenixCrystal7 and WoodWoseWulf
Analysis by PhoenixCrystal7
The Shiny Task Force is run by PhoenixCrystal7IvoryTinkler1 and SarcasmCloud
Contributing researcher count for Mega Raids: 63
Contributing researcher count for Shiny Ledyba: 63

Interested in participating in the Silph Research Group? Find out more, here!


¹To calculate the “certainty”, we first compute the probability of observing the exact number of shiny Ledyba from a binomial distribution at all previously observed shiny rates (also called the “likelihood”). The maximum likelihood for this data set is the Base Shiny Rate. We define the certainty as the ratio of the likelihood of this model to the sum of the likelihood of all models that were considered.