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Silph Study: #037

Published:
12.28.2020

Souvenir Survey: Universal Souvenirs

It’s been nearly one year since the Buddy Adventure feature was released along with a host of buddy-related bonuses. One particularly interesting bonus is the ability of Ultra and Best buddies to bring you souvenirs. Previously, the Silph Research Group took a close look at how a particularly rare souvenir, the Skipping Stone, is linked to OpenStreetMap water features. These findings laid the foundations for future research into the connections between real-world features and buddy souvenirs.

In this article, we will take a wider view of the souvenir landscape after researchers collected more than 9,500 souvenirs. Are there other souvenirs that are linked to real-world locations? Why are Tropical Flowers found in northern Norway? I’m nowhere near a desert, why does my buddy bring me Cactus Fruits? Silph researchers have uncovered the answers to these questions and more. Let’s get started!

Key Findings

  • There are eight souvenirs that your buddy has a chance to find no matter where you are: Tropical Flower, Flower Fruits, Cactus Fruit, Mushroom, Marble, Pretty Leaf, Stretchy Spring, and Torn Ticket.
  • These eight souvenirs fall into three distinct rarity tiers, with each tier being weighted half as much as the previous.
  • The other seven souvenirs are not found everywhere, and are likely tied to the location in which your buddy found them. Ongoing research is being done to determine what triggers each souvenir type.

Universal Souvenirs

There are eight souvenirs that appear to be universally available. That is, your buddy has a chance to find them no matter where you are. These eight souvenirs can be broken down into the three distinct rarity tiers that we’ll call Common, Uncommon, and Rare.

To visualize how we determined which souvenirs fall into this category, we’ve plotted the number of each souvenir found against the total number of souvenirs found by each researcher.



As you can see, once researchers were able to collect enough souvenirs they were virtually guaranteed to find each of these eight souvenirs.

Furthermore, these souvenirs are always available in the same relative weights to one another, with each tier being weighted half as much as the tier above it. Here’s how often each souvenir was found across the entire data set.

Souvenir Total Percent Est. Weight
Cactus Fruit 1,113 13.3% 4
Flower Fruits 1,048 12.6% 4
Tropical Flower 1,116 13.4% 4
Marble 570 6.8% 2
Mushroom 535 6.4% 2
Torn Ticket 263 3.2% 1
Pretty Leaf 249 3.0% 1
Stretchy Spring 263 3.2% 1

We evaluated whether there were any differences in rarity across locations using a chi-squared test of independence. There was no significant difference in the observed rate for each universal souvenir across locations with 100 or more souvenirs (0.16 p-value.) This gives us strong evidence to support a 4:4:4:2:2:1:1:1 ratio for the universal souvenirs. We cannot rule out the possibility that uncommon location factors may underlie the universal souvenirs as well. However, we would expect such factors to be common to most locations travelers would venture to. Researchers have collected 30 souvenirs or more from 68 locations around the world, and none were found to break the patterns shown here.

Buddy Species

Finally, we evaluated whether the species of the buddy Pokémon affected the distribution of the universal souvenirs. The ten most common buddy species along with the universal souvenirs they brought are shown in the following table:

Species Cactus Fruit Flower Fruits Tropical Flower Marble Mushroom Torn Ticket Pretty Leaf Stretchy Spring
Gible 58 62 66 34 22 16 15 7
Lucario 56 38 56 22 30 15 20 10
Deino 48 33 51 27 22 15 10 15
Mewtwo 37 37 50 18 17 11 8 12
Riolu 44 34 35 16 15 16 7 6
Togekiss 26 28 22 17 16 2 6 4
Sableye 27 27 35 9 14 4 5 4
Raichu_Alola 34 25 31 15 15 7 9 10
Pikachu 19 29 25 7 15 2 6 6
Metagross 24 16 26 8 10 4 2 14

We evaluated whether the observed distribution is independent of the buddy species using a chi-squared test of independence. This test gives a p-value of 0.12, which is not enough evidence to reject the null hypothesis that the universal souvenirs are independent of the buddy Pokémon species. One outlier in the data is the high number of Stretchy Springs found by Metagross buddies. More data will be required to determine if this result is the product of chance or an Easter egg.

Non-Universal Souvenirs

As discussed in our previous survey of the Skipping Stone, the availability of some souvenirs is tied to your location when the buddy finds the souvenir. We describe these souvenirs as “non-universal” souvenirs, which we believe require some location requirement to be fulfilled for a buddy to find it.

The following plot shows several souvenirs that fall into the “common” but non-universal category. Some researchers found these souvenirs more often than Cactus Fruits or Tropical Flowers at some locations, while others did not find them at all.

From the plot we can see that the non-universal souvenirs are more widely distributed than the universal souvenirs, indicating that another condition might be at play. Knowing that Skipping Stones are tied to real-world water features, it seems likely that similar criteria might apply to the other non-universal souvenirs, with Lone Earrings, Tropical Shells, and Beach Glass falling into the non-universal category.

While Silph researchers are pursuing several leads to determine what triggers these various souvenirs (for example, Tropical Shells and Beach Glass are always found near the coast), more investigation will be required to definitively show the conditions that allow your buddy to find a souvenir, and what the rarity is.

Until then, travelers, stay safe on the Road.


Acknowledgements

Authors: Lead Researcher CaroKann, Scientist Titleist, and Senior Researcher Sinkalingsveis
Analysis: Lead Researcher CaroKann and Scientist Titleist
Header: Lead Researcher CaroKann
Figures: Scientist WoodWoseWulf and Titleist
Editing: Lead Researcher CaroKann and Senior Researchers JamesBond00797 and RDC-DCIfan68
285 intrepid volunteer researchers collected data for this project. These 13 researchers went above and beyond the normal call of duty:

  • archer
  • Belle
  • CaroKann
  • DeeDillyDawn
  • Gustavobc
  • irisdapraia
  • JMcQueen81
  • Pancake
  • RDC-DCIfan68
  • Sinkalingsveis
  • skyeofthetyger
  • Titleist
  • TwitchToxin