The thought to spout out the book definition came to mind, but decided against it. "Surprise." He gave me a slight nod of his head to continue. "Being one step ahead of your opponent means they will be on the back end. With nonverbal, your opponent then has to rely on watching your wand or the spell itself. That means they won’t be focusing on other things," I licked my lips and then added, "it also allows you to chain spells together easily. Trying to speak the incantations, in battle, and wand movements require a lot of focus. Removing one variable from the equation makes it less taxing. Especially when you want to cast another afterwards."