"September Study on Spawn Behavior [Research]"

#PokemonGO: We are analyzing a dataset of several million spawns with the intent of increasing our knowledge of spawn mechanics, including what many refer to as Biomes. While we don't have any definitive findings on the Biome front yet, we have some interesting findings regarding spawn rates that can be shared. Some of this is supporting data for current theories, but a few conclusions are new:At least 97 species in the study-wide meta-biome show spawn behavior that is strongly dependent on the time of day. That is, they spawn at least twice as often at night as in the day, or vice versa. In our meta-biome, this is 40% of species and about 30% of spawns. Several other species show a mild dependence on the time of day, but that may be a side effect because several of the most frequent species that are time-dependent spawn more at night.All species with day/night dependencies shift at the same times in the evening and the morning. (previously proven, reconfirmed with this additional evidence).In this particular biome, the most common species with time-dependent spawns are all in Gen2, which is at least part of the reason why it was not as obvious before February. In the dataset, the most common time-dependent species were:Sentret (day) 4.05 MillionMurkrow (night) 4.03 MLedyba (night) 3.93 MHoothoot (night) 3.22 MTeddiursa (day) 1.63 MPast research has indicated that the day/night determination is based on the time of spawn. Our data has limitations because it contains "despawn time" rather than "spawn time". If the assumption that the time switch occur exactly on the hour, our data supports the theory of spawn time rather than despawn time (doesn't prove, but supports). Let me explain:In my initial analysis, I found that pokemon despawning between 22:00 and 23:00 local time was rather ambiguous, neither day nor night. A similar pattern occurred in the 10:00 to 11:00 hour.Previous research has proven that the most common spawn interval is 30 minutes, but not all.When I re-analyzed the data for the 22:00 hour into two half-hours, there was a clear delineation between the begining and the end, but it was not a clear step function. A despawn delineation at 22:30 fits the data much more consistent with the data than one at 22:00. But there is enough noise that I believe the real criteria is the time of spawn at 22:00, not despawn at 22:30.Spawns of some species show greater variability with time of day than others. We found 6 species where the variability was more than 4:1. Interestingly, these were all Gen1 species, with only one (Gastly) being semi-common:Starmie (night, N=1,596 spawns) = more than 5:1Gastly/Haunter/Gengar (night, N=276,000, N=16,800, N=1,049)Victreebel (day, N=1,291)Hypno (night, N=4,495)If a species and its evolution are both time-dependent, the evolution is sometimes more-time dependent than their unevolved forms. I did not find a single case where the opposite applied. There were several cases when I did not have a sufficient data volume of the evolved form, though. Examples are:Victreebel is more strongly time-dependent than Bellsprout or WeepinbellGengar more than Haunter, which is in turn more than GastlyGolduck (Psyduck is not time-dependent)Hypno more than DrowzeeStarmie (Staryu is not time-dependent)Ariados (Spinarak is slightly biased the other way, but not of statistical significance)Azumarill (Marill is slightly biased the other way, but not of statistical significance)Quagsire (Wooper is slightly biased the other way, but not of statistical significance)Here is the list of 22+ species with at least twice as many daytime spawns in our meta-biome:Bulbasaur / Ivysaur/ (not enough data points for Venusaur to be significant)Bellsprout / Weepinbell / VictreebelPonyta / RapidashExeggcute / ExeggutorTangelaJynxTaurosChikorita / Bayleef / (not enough data points for Meganium to be significant)Sentret / FurretHoppip / Skiploom / JumpluffSunkern / (Sunflora did not spawn)Snubbull / GranbullTeddiursa / UrsaringSkarmoryHere is the list of 25+ species with at least twice as many nighttime spawns in our meta-biome:Zubat / Golbat / CrobatOddish / (not enough data for Gloom / Vileplume, and Bellossum never spawned)Meowth / (not enough data points for Persian to be significant)Golduck (but NOT Psyduck)Gastly / Haunter / GengarDrowzee / HypnoStarmie (but NOT Staryu)Hoothoot / NoctowlLedyba / (but NOT Ledian)Ariados / (but Spinarak is slightly biased toward daytime)Azumarill / (but Marill is slightly biased toward daytime)Quagsire / (but Wooper is slightly biased toward daytime)MurkrowMisdreavusGligarSneaselInterestingly, four other spawning species are AS RARE OR MORE AS UNOWN (1:2,000,000) in this biome. For each of these (and unown), the sample size is small, so any difference less than the order of 1.5 times is not significant.Feraligatr (twice as rare)Flareon (not quite, but statistically twice as rare)Machamp (slightly rarer)Tyranitar (very slightly more common, but the difference is statistically insignificant)Caveats:The source of my data was a dump from a scanner, and consists of over 54 million spawns from over 120,000 spawn points in the (USA) central time zone. Spawns included in the sample occurred in August and September 2017 before the start of the recent event, and appear not to have been affected by any “event” spawn behavior.For the purpose of determining time dependent spawns, we only consider species with an average of more than 30 spawns in each hourly window (720 or more spawns) to be statistically validI do not condone or support the practice of scanning. However, once that data is public record, I believe that analysis of said data in the public domain is fair.(edit: minor text fixes) via /r/TheSilphRoad http://ift.tt/2xMWbXj