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Silph Study: #019


The Shiny Hunt: Raid Bosses and Community Day [Part II]

In Part 1 of our publication series The Shiny Hunt, the Silph Research Group established a base shiny rate for wild encounters. With that baseline firmly in mind, it’s time to proceed onward in our analysis to scenarios with boosted shiny rates! Specifically, Raid bosses and Community Day spawns. Buckle up and let’s dive in!

Raid Bosses

Raid battles quickly became a staple of many travelers’ Pokémon GO experience after their release one year ago. Since then, numerous potentially shiny Pokémon have made their way into the Raid boss rotation. Many have postulated a “Raid boss shiny rate” after observing an unusually high number of Raid boss shinies.

We are excited today to share that there in fact appears to be multiple distinct shiny rate boosts at play in Raid boss encounters!

Legendaries: Shiny Rate Boost #1

The most generous (and possibly clearest) shiny rate boost observed comes from the guardians of the sea and sky — Lugia and Ho-Oh.  Kyogre encounters are excluded from this analysis due to small sample size, but do appear to be trending towards the same rate.

From a total of 9,268 Lugia¹ and Ho-Oh encounters² we find an unprecedented shiny rate for these Legendary Pokémon of:

1 in 19

with a 95% confidence interval of 1 in 17 to 1 in 21. Shiny encounters among these Legendary Raid bosses were statistically distinct from other Raid bosses. But these are not the only shiny rate boosts appearing in the data…

Raid-Exclusive Species: Shiny Rate Boost #2

Another pair of Raid bosses stood apart in the data behind the Legendary guardians: Mawile and Absol!

So what’s so special about Absol and Mawile? These species started out as Raid-exclusive – meaning, the only way to originally acquire these Pokémon was through Raiding! Might we expect any future Raid-exclusive species to benefit from a similarly boosted shiny rate?

After recording Raid data on roughly 1,500 raids of each species, a clear distinction emerged that this duo was operating under a completely distinct shiny rate boost (and in fact may not even share the same rate with one another)! In contrast to the generous 1 in 19 for Legendary bosses, these species appeared at a rate of 1 in 35 for Mawile and 1 in 75 for Absol. Notably, the confidence intervals of these two species diverge significantly – warranting a closer look moving forward.

Event-Highlight Species: Shiny Rate Boost #3

Perhaps the most unexpected finding in the Raid boss analysis is the case of Aerodactyl! The fossil Pokémon was highlighted by name when it was promoted to Raid boss during Adventure Week 2018 and simultaneously began appearing in shiny encounters. In an unexpected twist, however, after 700+ Aerodactyl raids, the boss was found to have a clear, statistically significant boost in its shiny rate over other Raid bosses that can be found in the wild (like Sableye or Magikarp)³ – though not as boosted as the Legendaries’ boosted rate.

Thanks to the high volume of Aerodactyl raids Researchers racked up during the event, the data clearly reflects the distinctly boosted rate for Aerodactyl over its peers:

1 in 45

with a 95% confidence interval of 1 in 30 to 1 in 95. In contrast, data is not sufficient at this time to definitively claim the shiny rate for all Raid bosses – or even whether the other shiny Raid bosses appear more frequently than the wild encounter base rate.

What does this mean for future events? Might future new shinies receive an ‘event highlighted’ rate boost that makes them more achievable? Were this the case, Shellder would have been a strong candidate during the Water Festival (having received a similar promotion to Raid boss and shiny variant introduction). Perplexingly, however, we have no reports of shiny Shellder from Raid encounters. We don’t have enough data to determine whether this Pokémon isn’t available as a shiny from Raids, or whether our researchers have simply been unlucky thus far.

We certainly have reason to monitor future event Raid bosses closely to see if this ‘event highlight’ boost affects future Raid bosses!

Raid Boss Boosts: Summarized

For reference, the following table summarizes the findings for these 3 boosted rates:

Raid Boss Total Encounters Shiny Encounters Shiny Rate 95% Confidence Interval
Legendary Raid  9,268 492 1 in 19 1 in (17–21)
Mawile  1,627 48 1 in 35 1 in (25–45)
Aerodactyl²  707 15 1 in 45 1 in (30–95)
Absol  1,415 19 1 in 75 1 in (50–135)

A Pearson’s chi-squared test comparing Mawile, Absol, and Aerodactyl indicates that it is likely that these 3 Pokémon do not all have the same shiny rate (p=0.01). This statistical difference is primarily driven by the gap in shiny rates between Mawile and Absol, while Aerodactyl is not statistically different from either of the other two.

Additionally, we are unable to confirm whether the shiny rate for all other Pokémon available from Raids, such as Magikarp, Snorunt, and Sableye, is different from the shiny rate for wild encounters at this time.

Community Day

Another boosted shiny encounter rate is well-observed by now on the Road: the Community Day boost!

Previously, the Silph Research Group published a preliminary estimate of the Community Day shiny rate – about 1 in 23 with a fairly wide 95% confidence interval of 1 in (19-28) for the Pikachu Community Day. Based on data collected the past four Community Days, we are able to narrow this interval down even further. Our latest data now reveals the boosted shiny encounter rate for Community Day Pokémon is

1 in 24.5

with a 95% confidence interval of 1 in (23.7–25.3). It seems very likely that the shiny rate is either 1 in 24 or 1 in 25 based on this interval. Notably, no differences in shiny rate have been observed between the various Community Days.

Parting Words

This advancement in our understanding of shiny Raid bosses is an exciting discovery! But, as always, these findings underscore the need for further research to better understand and clarify the shiny rate boosts among Raid bosses.

We are also hopeful that in the upcoming Community Day(s) we’ll be able to conclusively narrow down the boosted rate to 1 in 24 or 1 in 25 – as this knowledge might assist in determining if shiny boosts are multiples of each other, as many would expect!

We hope these findings help inform your own shiny hunting efforts with a more solid understanding of the probabilities at play, travelers.

This concludes Part 2 of the Shiny Hunt publication series! Stay tuned for the final publication, Part 3, when we cover the last shiny rate boosts at play in Pokémon GO!


¹Four of these Raids were completed during the short period after the end of the Battle Showdown event when Lugia was mistakenly added back to the Raid pool. There were also many reports of shiny Lugia being temporarily unavailable at the beginning of the Eggstravaganza event. Because of the method of data reporting, we were unable to determine the exact start and end time of this anomaly, and therefore all data was left in the dataset.

²Nearly 3,500 of these observations were taken by a small group of trusted researchers who surveyed other travelers in their Raid team.

³Aerodactyl has only been available as a Raid boss as a potential shiny during Adventure Week thus far, so it is unclear whether this rate is valid outside of this event.