If you get a Togetic in Pokemon Emerald it can learn Mimic from the move tutor in Fortree City, then you can get a Togekiss with Mimic and Serene Grace by trading it to Gen 4 and evolving it. Then, in a double battle a faster Pokemon (like Prankster Whimsicott) can use Beat Up (it is not a status move but Prankster is helpful later) and Togekiss mimics it. The next turn you can use Tailwind to make Togekiss faster than most Pokemon and have it use the 6-hit Beat-Up (unless Whimsicott faints or has a status condition) with each hit having a 20% flinch chance thanks to King's Rock 10% doubled by Serene Grace. How often will the opponent flinch in this case?
A 20% flinch chance per hit happening 6 times has a 73.7856% chance of occurring (the math being (1-(8/10)^6)*100).