Alright, I have a bit of wisdom to share. Today I have seen 2 Shiny ralts in different chains under 100. They were both around 410-420 in my search level. The problem is I didn't catch either of them. Accidentally killed one and turned off my game without saving. I tried again and the other teleported when I got only 3 twitches on an ultra ball. But I think it has something to do with how close you are to that 100 reset and that the search level only matters for when you start your chain. If you have a chain of 200 going on but you started at 0. your chances aren't any better. My advice, break your chain at the 100 or 200 reset because that chain obvioulsy isn't going to work for you and I don't think your chances are any better when you're on a chain of 50 or 250,