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Silph Study: #042

Published:
02.09.2021

A Guide to Candy XL: Part 3 – Transferring

This article is the final installment in our three-part series discussing the various methods of obtaining Candy XL. In Part 1, we analyzed Candy XL drop rates from hatching eggs. In Part 2, we explored how Pokémon level influences the rate of Candy XL received from catching Pokémon. In this final article, we’re investigating what affects the chances of receiving a Candy XL when transferring Pokémon to Professor Willow. Let’s see what our researchers have uncovered and what questions are still left to be answered!

Key Findings

  1. Higher-level Pokémon are more likely to reward a Candy XL when transferred.
  2. The probability of receiving a Candy XL likely follows a stair-step model nearly identical to Candy XL obtained via catching.
  3. Candy XL is produced at a higher rate for transferring Purified Pokémon compared to transferring unpowered Shadow Pokémon (likely due to the significant increase in level.)

The Effect of Level on Candy XL

Since the GO Beyond update was released, our researchers have transferred a staggering 20,000 Pokémon for science. To better control for potential confounding variables, Pokémon were transferred one at a time in their obtained state— without evolving, trading, or spending stardust to power them up. We have not explored the effects of transferring Pokémon in bulk.¹ In addition to tracking whether or not a Candy XL was received during a given transfer, researchers also recorded the species, CP, and IVs, which were then used to determine the Pokémon’s level. The graph below shows the probability of getting a Candy XL as a function of Pokémon level.

As we discussed in our article on Candy XL from catching, there is a remarkable tendency for the Candy XL transfer rates to break off into distinct level ranges modeled by the blue dashed line.² Each “step” range above level 14 can be broken into clean factors of ⅛, meaning Pokémon above level 30 produced Candy XL at twice the rate of level 23 Pokémon and six times the rate of level 15 Pokémon! Transferring Pokémon below level 15 produced little to no Candy XL. Rates for each step range, along with their 95% confidence intervals, are shown in the table below.

Step Range Number of Transfers Avg. Candy XL per Transfer Estimated Fraction
Levels 1-14 8,363 0.027 ± 0.003 1/40
Levels 15-19 3,552 0.13 ± 0.01 1/8
Levels 20-22 2,512 0.25 ± 0.02 2/8
Levels 23-25 1,994 0.39 ± 0.02 3/8
Levels 26-30 3,425 0.48 ± 0.02 4/8
Levels 31-35 1,031 0.76 ± 0.03 6/8

The rate shown for each step range is lower for transferring than it is for catching, in part because a single catch can give multiple Candy XL, while transferring can only give one Candy XL. In over 20,000 observations, our researchers recorded at most one Candy XL per transfer, matching the single regular candy from transferring. This observation again parallels the proposed models for egg hatching and catching Pokémon, where there is a weighted chance for a Candy XL to be generated alongside each regular candy.

The Effect of Purification

Our researchers investigated one potential power-up mechanic in this study: purifying shadow Pokémon. When a shadow Pokémon is purified, it is instantly powered up from level 8 or 13 to level 25 at a discounted cost of stardust and regular candy.³ The table below shows the rate of Candy XL from transferring shadow and purified Pokémon.

Type Number of Transfers Candy XL received Probability
Shadow Pokémon 337 10 2.97%
Purified Pokémon 156 49 31.41%

The chance of receiving Candy XL is significantly higher for transferring purified over shadow Pokémon at base level (Fisher’s exact test, p-value<10-16). Notably, the Candy XL rate for transferring purified Pokémon is similar to the rate of transferring level 25 Pokémon, supporting the idea that the current level of the transferred Pokémon is used to determine the Candy XL rate.

Factors that did not influence transfer Candy XL

Other factors were examined for their possible effect on obtaining Candy XL. The following have not shown a significant effect thus far:

  • Pokémon transferred during the double transfer candy Spotlight Hours did not exhibit different Candy XL rates (Fisher’s exact test, p-value=0.35).
  • There was no relationship between Pokémon IVs and the amount of candy received after accounting for Pokémon level (tested using a logistic regression model, IV p-values>0.05).4
  • No relationship between Candy XL and Pokémon species or Pokédex number was observed, but more data is needed to draw a stronger conclusion.

Maximizing Candy XL Rewards

For species found in the wild, catching and transferring weather-boosted Pokémon, particularly those level 31 or higher, can be a great source of Candy XL. About 700 non-boosted Pokémon are required to reach the magical 296 Candy XL needed to power up a Pokémon to level 50 (including Candy XL rewards from catching, transferring, and converting regular candy to Candy XL at the 100-to-1 rate). However, this number drops to approximately 420 Pokémon if all Pokémon are weather-boosted. Pokémon above level 31 account for nearly 40% of the Candy XL in this hypothetical scenario, despite accounting for only 17% of the catches. In fact, if you were to only catch Pokémon above level 31, then a mere 175 catches are needed.

Additionally, the 100-to-1 conversion of regular candy to Candy XL is a surprisingly valuable source of Candy XL. If all Pokémon are caught with a Pinap Berry, the average number of required catches drops to around 650 and 400 for non-boosted and weather-boosted Pokémon, respectively. Fifty fewer catches is nothing to scoff at!

For species that cost 1,000 stardust to purify, you’ll trade approximately 2,900 stardust per additional Candy XL. Purification costs might be justified for some biome-specific species in this group for a small minority of travelers with an excessive supply of stardust. For Legendary Pokémon (with a substantial purification cost of 20,000 stardust), however, the cost to gain a single Candy XL exceeds 133,000 stardust after accounting for the opportunity cost of converting those 20 regular candies into Candy XL. We caution travelers against purifying Pokémon for the sole purpose of transferring without carefully considering their own resources and Pokémon availability.

With the exception of purifying Pokémon, this study only examined transferring Pokémon at their caught level, so we can only speculate whether or not the observed trends would apply to Pokémon that have been powered up. At this point, we caution travelers against investing resources to power up Pokémon for the sole purpose of transferring them. Even transferring Pokémon level 31 or higher does not guarantee a Candy XL, and stardust is a scarce resource for most travelers. Rest assured, our researchers will investigate the effect of powering up Pokémon on transfer rates in future studies. If you would like to donate your time and stardust to science, consider joining the Silph Science and Research Group!

Parting Words

We hope you enjoyed our three-part examination of the mechanics behind Candy XL, travelers! Candy XL has been a game-changing mechanic from the moment it was introduced, and the valuable data collected by our intrepid researchers has allowed us to more closely examine the various sources of this resource.

That’s it for now, travelers, but expect us to continue our exploration into more mysteries of Candy XL! Until then, stay safe and we’ll see you on the Road!


Acknowledgements

Article authors: Lead Researcher Gustavobc and Scientist CaroKann
Analysis: Scientists CaroKann and Titleist, and Lead Researchers Pancake and Gustavobc
Graphics: Scientists WoodWoseWulf and CaroKann
Project Leaders: Lead Researchers Pancake and Gustavobc
Editing: Scientists Cham1nade and skyeofthetyger
Data collection: Exactly 100 researchers collected data for this study. These 11 were favorites of Professor Willow:

  • Brush are Best
  • DeeDillyDawn
  • Lady Artemis
  • niktero
  • Pancake
  • pdxbatman
  • Rachies
  • Realms
  • Sean3116
  • superduperdrey
  • suziewrong

Footnotes

¹ Some travelers have anecdotally reported that they have observed an increase in Candy XL if a single Pokémon species is transferred en masse, as opposed to several different species. Niantic has confirmed that there was a bug in which Candy XL sometimes did not display in the UI when transferring several different species of Pokémon, and that this has been resolved in version 0.199. Regardless, the Silph Research Group will continue our investigations, and we’ll be sure to report back with any findings!

² As with catching, we evaluated the expected drops for various combinations of linear and stepped models using a chi-squared goodness-of-fit test at a significance level of 0.01. The model of stair-step growth provided a sufficiently good fit to the data. We were able to reject linear growth from level ranges 15-25, 15-30, and 15-35.  Further linear divisions of the level ranges tend to converge on the stair-step model.

³ The cost of purifying a shadow Pokémon ranges from 1-20 candy and 1,000-20,000 stardust, which is significantly cheaper than the 70 candy and 69,600 stardust normally required to raise a Pokémon from level 8 to level 25. Purification of Pokémon below level 25 raises their level to 25 and does not change the level of shadow Pokémon already level 25 or higher.

4 For multiple logistic regression, we estimated the log likelihood of receiving Candy XL as predicted by Pokémon level, the sum of IVs, and the product of IVs. Using a Wald test on the estimated coefficients for each variable in the regression, we found the sum of IVs and the product of IVs to be poor overall predictors (p-values=0.212 and 0.121, respectively). By comparison, the Pokémon’s level was an extremely good predictor for the likelihood of receiving Candy XL (p-value<10-16).