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Silph Study: #047

Published:
06.21.2021

A Guide to Candy XL Part 4: Trading

In true Douglas Adams style, we weren’t satisfied with leaving our “trilogy” at three. Welcome back to part 4 of the series — this time we’re examining trades! Candy XL was first earned in Pokémon GO by catching, hatching, or transferring Pokémon. In March 2021, Candy XL became an additional bonus earned from walking your buddy Pokémon or trading Pokémon with a friend. For trainers level 40 and above, every trade now has the chance to net one Candy XL in addition to any regular candy earned. The Silph Research Group quickly noticed that not every trade earned that precious resource, and we set out to solve the mysteries of the XL trading universe. Our intrepid explorers completed nearly 10,000 trades — here are their discoveries!

Key Findings

  1. The chance of receiving Candy XL from a trade is determined by the distance between the locations where the traded Pokémon were obtained.
  2. Neither Pokémon level nor special trade status influence the chance of obtaining Candy XL from trades.

Methodology

In order to examine what might affect Candy XL from trades, Silph Researchers recorded the species and level of both Pokémon involved in each trade, as well as the trade distance.¹ Researchers also noted special trades (shiny Pokémon, legendary Pokémon, or new Pokédex entries). This study only examines Candy XL drops for the researchers’ side of the trade; Candy XL obtained by the researchers’ trade partner is not included.

The Effect of Distance on Candy XL

Early reports from the Road indicated that trade distance was an important factor in determining the probability of receiving Candy XL. To test this, we first looked at the distance ranges that determine the yield of regular candy from trades, namely: one regular candy for 0-9.9 km, two regular candy for 10-99.9 km, and three regular candy for any trade over 100.0 km. The table below shows the rate of obtaining Candy XL for these distance ranges.

Regular Candy
Received
Distance
Range
Number of
Trades
Candy XL
Drop Rate
95% Confidence
Interval
1 0.0 – 9.9 km 4,413 9.8% 9.0 – 10.7%
2 10.0 – 99.9 km 4,069 25.0% 23.7 – 26.3%
3 100.0+ km 1,402 100.0% N/A

As the number of regular candies increases, so does the chance of obtaining Candy XL! Pokémon trades in the 10-99.9 km range produced Candy XL at over twice the rate of those in the 0-9.9 km range. Trading Pokémon caught over 100 km apart was even more profitable, as these trades always yielded one Candy XL.

While the distances associated with regular candy drops are an excellent predictor for Candy XL drops, might there be an additional effect for distance within smaller ranges? To test this, we divided our data into 5 km subranges for 0-9.9 km trades and 10 km subranges for 10-99.9 km trades. The graph below shows the observed Candy XL rate for each subrange, as well as a 95% confidence interval.

The Candy XL Drop Rate as a function of distance with a 95% confidence interval. The Pokémon trade distances are grouped into 5 km and 10 km subranges. The horizontal dotted lines show the Candy XL drop rate associated with the regular candy distance boundary.

As we can see in the graph, each subrange rate closely matches the rate associated with the larger regular candy boundaries. We found no significant deviation among the subrange rates within each range, and we suspect the marginal increase in the 90-99.9 subrange is due to sample noise.² In the end, it does not matter if you trade Pokémon from 25 or 85 km apart— both trades likely have the same chance of dropping Candy XL!

The Effect of Pokémon Level on Candy XL

In our previous studies involving Candy XL (catching, transferring, and walking), Pokémon level was an important factor in obtaining Candy XL. Could Pokémon level also affect trading?

In our study, we found no correlation between the Pokémon level and Candy XL drop rate. Using a multiple binary-logistic regression model, we tested the effect of Pokémon level and special trades on Candy XL drops. There was no significant relationship between Pokémon level and Candy XL.³ Likewise, special trades had no impact on Candy XL drop rates. It seems that distance is the most important factor when it comes to Candy XL from trades!

Parting Words

The introduction of Candy XL to trading has been a fun addition for traders and Candy XL grinders alike. As we have learned from this study, swapping Pokémon with catch distances over 100 km apart is the ideal way to guarantee obtaining Candy XL from traded Pokémon. But there are some additional factors to consider in selecting what you trade, if you are unable to find Pokémon from over 100 km apart.

When trading Pokémon caught less than 100 km apart, it is often more efficient to trade away low-level Pokémon and save the high-level Pokémon for transferring (where the higher level increases Candy XL chances). Ideally you would receive high-level Pokémon from your trade partner to then take advantage of the transfer Candy XL yourself. If you’d prefer to maximize both your and your friend’s returns, then we suggest swapping high-level Pokémon caught at least 10 km apart. It should be noted, however, that each trade partner has their own chance of receiving Candy XL with distances under 100 km, meaning it is possible for one trade party to receive Candy XL while the other party does not.

On top of hatching, catching, transferring, and walking, trading is now another important resource to help max out your Pokémon to level 50! Happy trading, and we hope to swap Pokémon with you out on the road!


Acknowledgements

Authors: Lead Researchers archer and DeeDillyDawn
Analysis: Scientists DarkMighty, constituent, and CaroKann
Project Leaders: Scientist DarkMighty and Lead Researcher archer
Graphics: Scientists WoodWoseWulf and CaroKann
Editing: Scientists skyeofthetyger and Cham1nade and Senior Researcher JinianD

Data collection: 40 trade-minded researchers contributed their Pokémon portfolios to this study. These 10 were our most high frequency traders:

  • Brush are Best
  • constituent
  • Daemare
  • DarkMighty
  • daronmoondog
  • DeathByToast
  • derekt75
  • Lady Artemis
  • nikosnina
  • SpelingChanp

Footnotes

¹ Pokémon Go stores the location of each Pokémon using S2 cell indexes rather than GPS coordinates. Each S2 cell represents an area of the globe where the Pokémon was obtained. For trade distance, a Pokémon’s location is assigned to the center of the S2 cell. For example, the trade distance between Pokémon A and B is calculated as the distance between the center of Pokémon A’s cell and the center of Pokémon B’s cell. This can result in trade distances being inaccurate by up to 10 km in comparison to the GPS coordinates. In addition, the trade distance shown in the trade menu is rounded to the nearest tenth of a kilometer. As such, a trade distance of 99.99 km would appear as 100.0 km in the trading menu but result in only 2 regular candy when traded. For the purposes of this study, we recorded each trade distance as it appeared in the trade menu.

The S2 cell size used to calculate trade distance varies based on the Pokémon’s encounter method. Pokémon caught in the wild and in raids use the center of the Level 10 S2 cell (roughly a 4 kilometer radius for the entire cell). Pokémon caught from field research encounters are centered on a Level 17 S2 cell (roughly 35 meter radius). Pokémon eggs are centered on the Level 17 S2 cell where they were obtained and keep this location once they are hatched.

² To formally test the uniformity of the 10-99.9 km range, we subdivided the distance into 10 km ranges, i.e. 10-19.9 km. We compared the number of Candy XL drops in each range to the number we’d expect if each trade had a 25% Candy XL drop rate. We found there was no significant deviation in the Candy XL counts across the 10 km subranges (χ²(7) = 7.51, p-value = 0.37).

Likewise, we subdivided the 0-9.9 km range into 0-4.9 km and 5-9.9 km subranges. We compared the number of Candy XL drops in each subrange to the number we’d expect if each trade had a 10% Candy XL drop rate. We found there was no significant deviation in the Candy XL counts across the two subranges (χ²(1) = 0.23, p-value = 0.63).

³ To test the effect of sent and received Pokémon levels and special trades on Candy XL, we applied a multiple binary logistic regression to trades in the two lower distance categories. In the 0-9.9 km category, the overall regression showed no significant impact of the predictor variables on Candy XL drops (χ²(3) = 3.5, p = 0.33). Trades in the 10-99.9 km category, again, showed no significant effect of Pokémon level or special trades on Candy XL drops (χ²(3) = 2.0, p = 0.56). Traded Pokémon in the 100+ km category always received one Candy XL, making such a test irrelevant for that distance group.