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Silph Study: #020


The Shiny Hunt: Egg Hatches and Field Research Rewards [Part III]

To date in our The Shiny Hunt series, the base shiny rate for Wild Encounters was first revealed to be roughly 1 in 450 (see Part I). Next, a variety of boosted Raid boss shiny rates were discovered and a more accurate Community Day shiny rate was calculated (see Part II). But there remain two additional ways to acquire shiny Pokémon we have not yet examined!

In this third and final installment in our series, we share new discoveries of boosted shiny rates in both: Egg Hatches and Field Research Encounters. Let’s dive in!

Egg Hatches

Hatching an egg on the Road is often a pleasant surprise – but one of the most exciting surprises in Pokémon GO is hatching a shiny Pokémon!

Since the Halloween 2017 Event, our Silph Researchers have donned their walking shoes and hatched 6,000+ eggs whose species had available shinies. Thus far, it remains unclear whether the base shiny rate for egg hatches is higher than the base wild encounter shiny rate of 1 in 450, but the data suggest a slightly higher base rate than in Wild Encounters.

However, in this analysis one surprising discovery did clearly emerge!

New Discovery: Baby Pokémon Shiny Rate Boost

There is a significant difference in shiny rate between baby Pokémon hatches and all other possible shiny Pokémon from eggs¹. For reference, the available shiny baby Pokémon are Magby, Pichu, Togepi, and Wynaut.

In all, our researchers hatched 1,442 baby Pokémon (specifically) over the course of this controlled study, of which 31 were shiny. This leads to a rate of roughly:

1 in 50

for baby Pokémon hatches, with 95% confidence interval that the actual shiny rate for baby Pokémon is between 1 in 35 and 1 in 70.

So what’s so special about baby Pokémon? These are the only available shiny Pokémon currently in the game that are “egg-exclusive“. Recall from Part 2 of the Shiny Hunt, the two originally “Raid-exclusive” Pokémon (Mawile and Absol) also had a boosted shiny rate above their Raid boss peers.

As a matter of fact, the shiny rate for baby Pokémon is surprisingly similar to the shiny rates for the boosted Raid bosses Aerodactyl, Mawile, and Absol! Is it possible that at least two of these categories are using the same boosted shiny rate?

Field Research (Quest) Encounter Rewards

The final shiny rate boost left to explore is in Pokemon acquired from Field Research encounters.

Several potentially shiny Pokémon have made an appearance as Field Research rewards since the feature’s release in late March 2018. Research is still actively ongoing to determine whether all reward encounters have a higher shiny rate than the wild encounters, but the advent of Adventure Week afforded Silph Researchers a rare chance to collect a high volume of encounter rewards for two species.

With that data two clearly boosted rates from Field Research appeared: Aerodactyl and Absol!

During Adventure Week, an Aerodactyl encounter was rewarded for completing the task “Evolve an Omanyte or Kabuto.” Silph Researchers completed 6,390 of these tasks and found 108 shiny Aerodactyl in the process. This gives a shiny rate of approximately:

1 in 60

with a 95% confidence interval of 1 in 50 to 1 in 70 for this encounter type. Curiously, the Aerodactyl shiny rate from Field Research was indistinguishable from its Raid boss shiny rate during this event².

Absol encounters are rarer, but Researchers have still managed to acquire and record 153 reward encounters. This is not sufficient to approximate any boosted shiny rate for Absol, but it is sufficient to confirm that its encounters also had a higher shiny rate than the base shiny rate of 1 in 450. Of the 153 controlled encounters, 3 shiny Absol appeared. Were Absol encounters to abide with the base shiny rate (1 in 450), there would be less than a 0.1% chance of this many shinies appearing³. It is also too early to know if Absol Field Research encounters have the same shiny rate as the Absol Raid shiny rate reported yesterday.

As more data is included over time, we anticipate more clarity on these shiny rate boosts in Field Research. But thanks to Aerodactyl and Absol, the Field Research encounter shiny boost has been identified and will now be studied in greater depth!

Putting it All Together: All Known Rates & Boosts

Thank you for joining us on this three-part analysis of the various shiny rates at play in Pokémon GO!

We’ve answered a lot of questions about shiny Pokémon during this adventure. Here are some of the highlights:

  1. The base shiny rate for Wild Encounters is roughly 1 shiny in every 450 encounters
    • This rate is unaffected by the many Special Events that feature shiny Pokémon, the species of Pokémon, and the weather
  2. Three distinct Raid boss shiny rate boosts are now known
    • Legendary Raid bosses: Approximately 1 in 19
    • Raid-Exclusive Pokémon (e.g. Mawile, Absol): From 1 in 35 to 1 in 75
    • Event-Highlighted Species (e.g. Aerodactyl): Roughly 1 in 45
  3. Community Day’s shiny rate boost was narrowed down to: Between 1 in 23.7 and 1 in 25.3
  4. Baby Pokémon enjoy a boosted shiny rate: Approximately 1 in 50
  5. Field Research encounters for Aerodactyl and Absol were significantly boosted
    • Aerodactyl: Roughly 1 in 60
    • Absol: Rate definitively boosted, but specific rate not yet confirmed

And for a tabular view of these findings with all current 95% confidence intervals:

Method Est. Shiny Rate 95% Confidence Interval
Base Wild Encounter 1 in 450 1 in (425–475)
Legendary Raids 1 in 19 1 in (17–21)
Community Day 1 in 24.5 1 in (23.7–25.3)
Mawile Raids 1 in 35 1 in (25–45)
Aerodactyl Raids 1 in 45 1 in (30–95)
Absol Raids 1 in 75 1 in (50–135)
Baby Hatches 1 in 50 1 in (35–70)
Aerodactyl Field Research 1 in 60 1 in (50–70)

While these new discoveries answer a lot of questions and dispel many myths, they also lead onward to new questions and follow-ups! Namely, our data indicates that different Pokémon available through Raids, hatches, and Field Research encounters not highlighted above may not enjoy any boost in shiny rate. As clarity on these rates develops further, additional research findings will follow.

Danger Zone: Speculation!

Note: What follows is a hypothesis at how these findings might fit together. Proceed with caution, travelers – this conjecture is likely to change with more data!

We believe this data provides more than sufficient evidence that shiny rates are not limited to powers of 2 like 1 in 256 or 1 in 512.

The strongest evidence for this lies in the now well-established shiny rate for Community Day (1 in 24 or 25) and, to a lesser extent, the Legendary Raid shiny rate (1 in 17 – 21). The 95% confidence interval (or even the 99.9% confidence interval!) simply doesn’t come anywhere close to a power of 2 for the known Community Day shiny rate.

Assuming that shiny rates are not limited to powers of 2, we might speculate that another integer value is instead employed as the denominator of the base shiny rate which would be divided to derive each of the “boosted” rates. Were this so, the Legendary Raids shiny rate might likely be 1 in 20 while Community Day might be 1 in 25. Assuming these are correct, we could proceed onward to speculating the less certain boosted rates with compatible multiples.

The base shiny rate for Wild Encounters is a little trickier. At first blush, 1 in 450 seems like a relatively nice round number to use. But two pieces of evidence lead us to speculate that this may not be the exact value used:

First, the Legendary shiny rate of 1 in 20 is not an even multiple of 1 in 450.

Second, while we stress to our researchers the importance of keeping good records and not biasing their submissions, it is simply too easy to lose track of the Pokémon species you are counting, particularly when you have not received any shiny Pokémon. Nearly 1,000 researchers contributed data to this project, and while many layers of error-checking were used, removing slightly biased submissions is nearly impossible.

Evidence for some bias in our reporting can be seen when we compare the shiny rates for our newest researchers (who make up a slight majority of our data), and our more seasoned, senior members. Our junior researchers have a shiny rate of 1 in 425, while our more experienced seniors have a shiny rate of 1 in 475. As you might expect, if the probability was actually lower than our reported value, the seniors are closer to the true rate than our junior members. We could therefore speculate that the actual integer value being used is 1 in 500 for the base Wild Encounter shiny rate.

Extrapolating even further, all the other boosted shiny rates for Field Research, hatches, and Raids might be boosted to 1 in 50. (10 times the base rate). The significant difference between Absol and Mawile rates reported in Part 2 of this series could be consequence of chance or, though unlikely, the result of reporting bias in our Mawile reports over Absol reports.

One final speculation we would put forward is that the shiny rate is independent of the method of obtaining the Pokémon, dependent only on the Pokémon species. As noted previously, the preliminary shiny rate for egg species, Raid bosses, and Field Research encounters that are also available from Wild Encounters are similar to the shiny rates from Wild Encounters.

The takeaway: we don’t have all of the answers yet! Perhaps there is no common multiple between shiny rate boosts at all. But the Research Group will continue our work collecting data on shiny Pokémon for many months to come, and our understanding will continue to grow.

Parting Words

Shiny Pokémon remain one of the rare jewels of the Pokémon collector’s eye. But there is still much to learn about these special Pokémon in all their various encounter scenarios!

We hope these discoveries and new knowledge of shiny rate boosts will help inform your collecting strategy, travelers. Remember, at the end of the day the number one tool in your backpack is perseverance.

Stay tuned for future updates to these analyses. With more data comes greater clarity and exciting new discoveries!

Happy hunting!


¹We checked whether this difference was driven by an increased shiny rate for baby Pokémon during the Eggstravaganza event. Our researchers hatched 351 baby Pokémon during this event, and were rewarded 5 shiny Pokémon. This falls well within the expected range for the 1 in 50 rate seen across all events.

²A Pearson’s chi-squared test comparing the Aerodactyl Raid shiny rate to its Field Research shiny rate gives a p-value of 0.66.

³This p-value is based on a two-tailed Fisher’s exact test between Absol encounters and all other Field Research Encounters.  The exact p-value was 0.0061. We used this test instead of a Pearson’s chi-squared test because of the small sample size.