>>42416631it kinda does. the encounter system works in that the odds go higher and higher the more pokemon you slap in the face (50, 100, 200, ect.) until 500's max odds (1/682 w/o charm and 1/512 with charm). however instead unless of it being 100% of the higher odds, it's only a 3% chance (maybe, we don't know if this is intended or a fuckup).
the thing is is that the person who found this out was mr serebii himself, and whenever someone tries to question him on where he found it and to show it, he just kinda shies away from it. personally i'm in the boat that it's true until proven otherwise
in other words, you're pretty much doing full odds with a small chance of the mon you want being in your favor.
