"Modelling the ex-raid invitation process"

#PokemonGO: The ex-raid invitation process right now seems really chaotic and illogical right now, but I feel it is possible to make some sense out of it. Here, I present a possible model for what might be happening.Algorithm:A date in the past (henceforth referred to as dday) and a gym (henceforth referred to as g-gym) are chosen at random.All players who raided at g-gym on d-day are invited with probability 1/(Nₚ)x , where Nₚ is the number of gyms player p raided at on d-day, and x is a number between 0 and 1.Motivation for 1/(Nₚ)x is that during an earlier interview, Niantic’s software engineering director Ed Wu mentioned that they want to reward players who do "raid battles almost every day". If this was the aim all along, setting x=1 means that all players who raid at least once a day will have equal probability of receiving an invite, regardless of how many raids they do each day. Setting x=0, on the other hand, makes it such that the probability of getting an invite is simply proportional to the number of gyms raided. While the statement by Ed Wu does suggest x=1, this does not reward players who do lots of raids, hence a value somewhere between 0 and 1 seems to make sense -- it means players should try to raid daily, with additional raids done giving diminishing returns in regard to the probability of getting an invite.This model, with x close to 1, does explain some of the observed phenomenon:Levels of invited players seem to follow a bell curve centered somewhere around lvl30. Since the number of raids done a day has minimal impact on the likelihood of receiving an invite, the level distribution of players invited will roughly follow the level distribution of active players, rather than favouring hardcore players with thousands of raids completed.Invited players find that fellow invitees had participated in the same raid as them. If there was only 1 raid at g-gym on d-day, all the invited players must have completed that particular raid.Players find that their smurf accounts all received an invite, while their main did not. If their smurf accounts only did one raid that day to clear the pass, but their main went on to hit a bunch of additional raids, the smurf accounts will all receive the invite while the main only has a small chance of getting it.Overall, this may not be the exact protocol for inviting players, but the actual process may very well be something along this line. At the end of the day, ex-raids are still in the testing phase and subject to change anytime, but I believe this is something worth thinking about. via /r/TheSilphRoad http://ift.tt/2AccoaR