World Tourism Day: Zangoose and Seviper Shiny Rates

Greetings, travelers! The latest Pokémon GO event celebrates World Tourism Day with the release of the Shiny forms of the regional-exclusive Pokémon Zangoose and Seviper. Additionally, travelers may find the event-exclusive Field Research Task, “Trade Pokémon caught 10,000 km apart”, which rewards the Pokémon that is not normally native to your region (with some exceptions near the borders). Silph researchers have once again answered the call of duty and promptly started investigating their shiny rates. We have some interesting findings to share already!

9/28/2019 20:00 UTC Update

Late last night, we put forward a hypothesis proposing that the shiny rates of Zangoose and Seviper were dependent upon whether they were in their native or non-native regions.

After deeper analysis, this hypothesis has now been proven false. To be clear, we now know there is no significant statistical difference between the shiny rates of Zangoose or Seviper from their native vs. non-native regions.

While our data collection procedures were solid and have helped us approximate whether standard Seviper/Zangoose spawns were boosted, an error in the post-collection analysis unfortunately attributed some shiny Pokémon to the incorrect region.

While the Research Group takes pride in the high-quality analysis we are known for and the huge organized efforts that go into studying PokéScience in the Group, we also want to make sure to own any errors or inaccuracies in our analysis and live up to our goal of illuminating the mysteries of Pokémon GO as a trustworthy and up-to-date source.

The accurate number of encounters and shinies found after aggregating both species are 8,977 encounters and 24 shinies, leading to a 99% confidence interval of 1 in 230 to 1 in 675. These data do not provide sufficient evidence to support a boosted shiny rate. We’ll keep these numbers updated as the event progresses.

See you on the road, travelers.

9/28/2019 4:30 UTC

So far, researchers have encountered over 7,500 Zangoose and Seviper from Field Research Tasks and out in the wild. Aggregated, the data indicate that the shiny rate is slightly above normal (around 1 in 330 for 23 shinies), but we couldn’t rule out that the base shiny rate wasn’t in play. However, one of our clever researchers had an interesting hypothesis: what if the shiny rate was boosted only for your non-native species. This would indicate a separation of shiny rates by region, not necessarily by method.

The data were not collected to specifically test this hypothesis, so we attempted to infer the region of our researchers by comparing the total number of Zangoose and Seviper reported. The higher value was presumed to be native and the lower value non-native for each researcher¹.

The results of this analysis and the confidence intervals around their shiny rates are as shown below:

Encounters Shinies 99% CI (1 in )
Native 7,036 13 290 – 1260
Non-native 578 10 30 – 155

While the method of separating researchers is imperfect, these results show a clear delineation between the two groups. This difference is much larger than would be expected by chance (Fisher’s exact test p-value < 0.00001). The species native to your area appears to be using a shiny rate near the base rate, while the non-native species is enjoying a large boost.

We attribute the cause of this “split” shiny rate to the location, rather than the method of obtaining. A location-dependent shiny rate has precedents in Safari Zones, GO Fests, and Community Days, while no differences in shiny rates by method of obtaining a Pokémon have ever been found.

Stay tuned for updates as we collect more data to confirm the split shiny rate hypothesis!