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Silph Study: #015


How Bonus Candies Are Awarded For Berrying Gyms

Shortly after the new gym system was released, reports flooded in that feeding berries to gym defenders would sometimes reward a candy of that species’ family (alongside the standard reward of 20 Stardust). 

Interestingly, this bonus candy drop is rather uncommon, so the precise probability has remained unknown. The recent efforts of the Silph Research Group, however, have shed some light on this topic.


Over the past few months, 240 researchers fed over 100,000 berries in a controlled study and received over a thousand candies for their valiant efforts! Using this data, we are able to say with 95% confidence that the expected chance interval of receiving a candy from feeding a defending Pokémon a berry is:

(1.20 ± 0.06)%

Or roughly 1 in 85 berries.  Here’s a look at the raw numbers:

Berries Fed Candies Obtained Percent
113,502 1,365 1.20%


We also examined the potential influence of the following external circumstances:

  • Gym Medal (Vanilla, Bronze, Silver, or Gold)
  • Berry Type (Razz, Golden Razz, Nanab, or Pinap)
  • Species
  • Remote Feeding
  • The defender being your own Pokémon
  • The CP increasing after feeding

We found that NONE of these variables have any observable effect on the candy drop rate!


Each berry fed in this study was also recorded alongside several possible influencing factors (mentioned above): the trainer’s gym medal rank, the berry type, the species being fed, whether it was fed remotely, whether the researchers were feeding their own Pokémon or another trainer’s, and whether motivation was restored by the feeding or not. We checked whether the rate of awarded candy was independent of each of the potential influencing factors with a Pearson’s Chi-squared Test, with an alpha value set at 0.05. If the p-value of the test is greater than 0.05, then there is not sufficient evidence to conclude that the factor has any influence on candy drop rates.
This is what we found:

Badge Berries
No Badge 204 1 0.49%
Vanilla 5,766 62 1.08%
Bronze 14,699 162 1.10%
Silver 53,497 670 1.25%
Gold 39,336 470 1.19%

Pearson’s chi-squared test p-value = 0.365


Pokémon Owner Berries Fed Candies Obtained Percent
Me 49,054 612 1.25%
Someone Else 64,448 753 1.17%

Pearson’s chi-squared test p-value = 0.137


Remotely Fed Berries Fed Candies
Yes 71,737 831 1.16%
No 41,765 534 1.28%

Pearson’s chi-squared test p-value = 0.088


CP increase Berries
Yes 87,334 1,068 1.22%
No 26,168 297 1.13%

Pearson’s chi-squared test p-value = 0.238


Berry Type Berries
Razz Berry 49,876 595 1.19%
Nanab Berry 45,038 548 1.22%
Pinap Berry 17,463 207 1.19%
Golden Razz Berry 1,125 15 1.33%

Pearson’s chi-squared test p-value = 0.884


Species* Berries
Candies Obtained Percent
Blissey 23,639 291 1.23%
Chansey 4,679 58 1.24%
Dragonite 8,923 102 1.14%
Gyarados 4,165 49 1.18%
Larvitar 3,834 53 1.38%
Snorlax 13,130 168 1.28%
Tyranitar 11,244 126 1.12%

Pearson’s chi-squared test p-value = 0.808

* Species list filtered to only include those with 3000+ data points

Parting Words

With these findings in hand, our travelers now know how often bonus candy should appear, and that there is no need to worry about strategizing to increase your bonus candy drop rate! Just remember that each berry has an independent chance of receiving a candy drop. Receiving 2 or 3 candies in a short time period as well as experiencing several hundred candy-less feedings are very possible. It’s easy to imagine a “lucky” species or berry, but …it’s all a random pull from a hat!

Happy berrying, travelers.


Some have hypothesized that the bonus candy drop rate may be altered during or after events.

Fortunately, the data collected spanned the Halloween event, including the pre- and post-event periods.  After grouping and examining the relevant periods, it can be concluded that the drop rate has not changed over the pre- and post-Halloween periods.

Period Berries Fed* Candies Obtained Percent
Pre-Halloween 74,955 911 1.22%
Halloween 8,135 113 1.39%
Post-Halloween 27,480 322 1.17%

Pearson’s chi-squared test p-value =0.363 

* The number of berries does not add up to the total of 113,502 as time periods around the event changes (Oct 21, 7pm UTC and Nov 2, 8pm UTC) have been excluded to ensure data integrity