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Silph Study: #010


New Changes to Egg Species: September 2017

The Silph Research Group's large-scale study of egg drops in Pokemon GO has confirmed new changes to egg species (and their rarity).

Four months ago, the Silph Research Group discovered Pokemon GO's secret egg rarity tiers and, two months ago, observed the first recorded changes in the rarity tier chart describing all currently hatchable eggs.

We are now confident that changes occurred at the beginning of the Anniversary event on July 7th, with a minor change occurring at the event's end on July 23rd:

  • 9 species have recently stopped appearing in eggs
  • 13 species have been added (or restored) to eggs
  • the rarity and egg distances of several species have been changed

Additionally, the final and rarest tier has now been confirmed, per our suspicions months ago. Consequently, we have changed our nomenclature and have replaced ULTRA-RARE with SUPER-RARE; thus we call the newly confirmed rarity tier HYPER-RARE.

Without further ado, here are the latest changes:

Species Removed from Eggs

The following nine species are confirmed to no longer hatch from new eggs:

These species (notably including the Generation I starter species) ceased appearing in new eggs at or soon after the beginning of the Anniversary event on July 7th. Eggs acquired and hatched in the subsequent periods, including post-Anniversary event, continued to lack these 9 species.

In total, 2,646 eggs were collected during the Anniversary event, and 4,054 after the Anniversary event by Silph Researchers without these species appearing.

With the exception of Yanma, which was dropped from the Super-Rare tier, the removed species were all either Common or Uncommon hatches previously.

Species Newly Added to Eggs

The following thirteen species are confirmed to have been added to eggs at the beginning of the Anniversary event:



Notably, Chinchou was added initially as a 10km egg on July 7th, but was moved to the 5km egg group on July 23rd.

Species With Egg Distance Changes

Four species have had their egg distance changed at the end of the Anniversary event:

  • Chinchou - Changed from a 10 km egg to a 5 km egg
  • Mantine - Changed from a 10 km egg to a 5 km egg
  • Pineco - Changed from a 10 km egg to a 5 km egg
  • Gligar - Changed from a 10 km egg to a 5 km egg
Species That Have Become More Common

In addition to the thirteen species recently added to egg hatches, four species have become more common:

  • Pichu - Changed from Uncommon to Common. This may have been to assist those hunting a Pichu in the limited edition 'Ash hat' form. It is also helpful for those currently hunting the rare shiny Pichu
  • Mareep - Changed from Rare to Uncommon
  • Porygon - Changed from Super-Rare to Uncommon
  • Skarmory - Changed from Super-Rare to Rare

Mareep's change is a particularly welcome one for many travelers still struggling to collect enough candy for its third evolution, Ampharos.

Species That Have Become More Rare

Finally, two species have been made more rare in this change:

  • Pineco - Changed from Uncommon to Super-Rare
  • Gligar - Changed from Uncommon to Super-Rare

Not only have these two (generally undesirable) hatches been made less common, they've also been moved from 10 km eggs to 5 km eggs, as noted above - a welcome change on both fronts!

New Rarity Tier Chart

So, with the above-mentioned changes in mind, travelers, here is the latest rarity chart as verified by the Silph Research Group!

Rarity Tier Species
16/508 = 3.1%

8/508 = 1.6%

4/508 = 0.8%

2/508 = 0.4%

1/508 = 0.2%

To view all hatchable eggs by rarity tier and egg distance, you can reference the Silph Road's official egg resource:


Note 1:

The Silph Research Group hatched 267 eggs at GO Fest in Chicago. This is far too small of a sample to determine the individual rarity tiers at this event. However, when pooled together there are no apparent changes beyond many species' distance change to 2 km eggs.

Parting Words

These were large changes, travelers, and ones that appear to have improved the egg pool (apart from Natu and Wooper, of course). The current 10km egg pool contains very few undesirable species - an improvement we're excited about!

We owe many thanks to the hardworking folks in the Silph Research Group for pounding the pavement and contributing their data in the Silph Research Group's controlled setting.

Happy hatching, travelers!


This finding was shared on our subreddit on September 2, 2017.