>>30642907>ChainingSeeing pokemon consecutively. Means different things fire different games. This game it means SOSing. The chain number means that's how many encounters you've had in the chain
>SOSWhen the pokemon calls for help
>MMMasuda Method. Basically means you're bedding for a shiny.
If you have pokemon from different regions in the day care, you're chances of a shiny hatching from one of their eggs are much better than 2 random mons.
I might be wrong but I think it goes from 1/4096 to 1/512
Serebii can tell you for sure
MM is most popular because you can guarantee assume things about the pokemon (IV, nature, etc)