So at this point in time, what are the paths that pokemon use to go through generations. I'm thinking of shit like Pal Park to transfer from the GBA games to Pearl and Diamond, which is the only one I actually know of.
I'm mostly curious about transferring between gen 4 and 5. Since they're all regular DS games, can you just use IR to trade?
And as a side question. Assuming one had all the necessary peripheral shit, how far back could you reach for a pokemon?