What Are the Odds...
100% shiny pikachu, with Surf.
Answers
You also need to considerate the probability of the spawpoint spawning a Pikachu.
Spawn needs to be Pikachu
Pikachu needs to be 100%
Pikachu needs to be shiny
Chance of this event is far lower than 1/65536, however, the chance that i am talking about is for every specific spawnpoint. You can "visit" more spawnpoints to make your chances of finding a Pikachu in the first place higher
No, it is still 1/256 because when te egg drops, it must be Kyogre, there is no other mon that can currently spawn from a tier 5 egg. However there are many mons that can spawn on a specific spawnpoint, but maybe i am wrong on this one...
Edit: you cannot go to a specific spawnpoint and know that it is going to spawn a Pikachu.
You can however go to a specific gym and know (because you see the egg) that it is going to spawn a Kyogre.
Therefore, the chance of the raid spawning Kyogre is 1 and the chance of the spawnpoint spawning a pikachu is well, less than 1.
Well maybe it is a bad example but you clearly got my point- tier 5 eggs are different, but lets say its a tier 4 egg, the chance of catching a 100% golem goes down because it hatched a tyranitar?
The fact that you have already committed to doing something (e.g. doing a golem raid) make the egg hatch irrelevant. Same how the OP is committed to the Pikachu, makes the spawn 'irrelevant' (by that I mean he will not be looking at pidgey, rattata
Perhaps your answer is to the question 'what are the odds of catching a 100% shiny Pikachu without knowing what spawn I am clicking on', because you won't be clicking on magikarp if your aim is to get the 100% shiny
If you want to be cute about it the OP isn't catching one pokemon either for his whole event, so you have to multiply the amount of times Pikachu is caught and compute new odds but lets not go there