There is something missing. I went to Bulbapedia. Like Acrobat can do double the damage if the user is not holding any item. Also, I would like for in the future, a Fifth Generation Damage Calculator have the same features from the IV Generation one and add new abilities. But please do so once you get the most accurate effects of the items, moves, abilties of the V Generation.

We'll look into this once more research has been made into the exact effects of all the attacks, items and abilities.