"What may have happened with the current round of EX raid invites"

#PokemonGO: I've been running around with this crazy theory that EX raid eligibility criteria has a bug and is working backwards - lower gym badge, less raids done, lower player level have a higher chance at receiving an EX invite, a direct opposite of what they claimed. Not on purpose but because of a bug.From Niantic's standpoint it would actually be quite difficult to notice there is a bug - everything is cool when you look at the big numbers, trainers are getting the expected number of invites etc. Because of the semi-random nature of the selection it is expected that some low-score trainers would be invited too, so all numbers would look kinda-ok.The reason it was kinda-working is that there was some "pre-filtering criteria" - the algorithm would select players who did a raid at the gym recently (last week), then semi-randomly select, say, 50% (weighted by their "score") and give them EX passes.What has happened now is that they removed the "pre-filtering criteria" to give a fair chance to players who have a high badge/did a lot of raids at the gym, but not in the last week. It seemed like a safe change because they thought the algorithm works correctly - the high-score players would be weighted very heavily and someone who just spun the gym six month ago will have a teeny-tiny chance. This actually would be a good change and would be fair to players who spent hundreds of dollars on raid passes, it would give them a chance of those raids they did a few months ago to produce an EX invite.But because the weighting algorithm was broken from the beginning the passes predominantly went to people who only interacted with the gym briefly a long time ago.So that's what I believe has happened.One positive side-effect of this may be that Niantic finally realises there is a bug in their Ex-raid invite generator script and fixes it.Here's an article on weighted random selection - the bug is in the code which does something like the code in the article. via /r/TheSilphRoad http://ift.tt/2E7UV5C