Board Thread:Tips, Tricks, and Questions/@comment-11306821-20130627015437/@comment-6160230-20130627115451

100% Perfection means 2 monsters both at max level and 4 specials at max level. As you level these monsters/specials the perfection % will increase depending on what level your monsters are. This is a pretty basic explanation, you can read more about the calculations of perfection through the FAQ section (Tap yourself, Click the cogwheel, click Help and click on Evolution)