I feel like the base chance with maximum boost but minimal chain and no zthon crystal is around 1 in 4000.
So arceus ranks can push that up to 1 in 800.
But that's just a feeling. I'm usually luckier than that while my friends aren't.
Also I saw very long chains of max boosted people that got a bit more than 1 melan per 1000 eggs
Yeah, I'll use Meu's huge Eevee chain just due to sample size:
1441s/223a/38m/36347
That's about a 1/25 shiny chance, which I experience as well. 1/162 for Albinos, which seems fairly accurate as well. Theoretically, this would put your melan chance at 1/4075 using these odds, but obviously, with an experimental average melan rate of 1/957, there's a big difference there.
In my current chain, I've hatched 4 melans so far, beginning with the melan included at the start of this thread. From 4854 to 5549 (giving me a 1/174 chance of a melan during this stretch). I think this can be attributed to a significant stroke of luck (thank Sally), but it
does prove the usefulness of long chains, I think.
(Side note that I don't have Arceus nor use Z-Crystals, but I do charge my radar on max and use a shiny charm every day.)
