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Silph Study: #011


December Egg Species and Rarity Changes

Since the Equinox event ended on October 3rd168 Silph Road Researchers have hatched 6,172 eggs (a total of 27,804 km egg distance!) in the Silph Research Group’s study of egg mechanics.  An update has been long overdue to the official Silph Road egg distribution information – and today that update is here!

While much has remained the same, three new Generation III  ghosts were added to the egg pool during the Halloween event and one Pokemon may have changed its rarity tier. Our findings are not conclusive yet for the Super-Rare and Hyper-Rare tiers and they could change as more data comes in.

Here are our latest findings:

Species Newly Added to Eggs

Duskull and Shuppet were added to 5 km eggs and Sableye was added to 10 km eggs at the beginning of the Halloween event.  We currently have no reason to believe (and fairly strong opposing evidence) that any other new species additions have occurred.

In examining hatches after the Halloween Event, Generation III ghosts (Sableye, Duskull, and Shuppet) have appeared in frequencies consistent with the Rare tier.

Species That Have Become More Common

While evidence is not fully conclusive, data collected since our last egg distribution update suggests that Shuckle is 500 times more likely to be in the Super-Rare tier than its previous Hyper-Rare tier classification and it is the opinion of the Research Group that this is now its proper rarity tier.

What did not change

At present, our findings appear to confirm that (excluding Shuckleall prior rarity tiers have remained the same with all previously hatchable species remaining in the egg pool.

Current (Comprehensive) Rarity Tiers

The current egg rarity tier and distance chart has been updated on and is included here for your reference:


16/521 = 3.1%


8/521 = 1.5%


4/521 = 0.8%


2/521 = 0.4%


1/521 = 0.2%


Note 1: How Do Eggs Actually Work?

While common knowledge for our veteran travelers, it is valuable to remember (especially for new faces on the Road) that:

The Pokémon in an egg is decided at the moment you spin a stop or gym and receive an egg. According to our current knowledge, the server decides which species the egg is (according to the rarity tiers above) and reflects the corresponding egg distance (2 km, 5 km, or 10 km) for that species.


That’s it for this time, travelers!

Our hard-working and ever-walking Researchers will continue to hatch eggs and monitor any future changes – especially with the advent of Gen III in coming weeks.

Until then, travel safe!