To help you keep track of your learning, and help you determine where to focus your study efforts, Brainscape has created a "Mastery" statistic at both the Deck and Class level.
Your Mastery is a weighted average of your confidence in all the cards in the specified Deck or Class. If you have not yet studied any of the flashcards, your Mastery would be 0%. If you had marked a 5 (perfect confidence) for every flashcard, your Mastery would be 100%.
Caution: While your goal is to gradually move all cards studied to a confidence level of 5, don't get too excited by watching the progress bar move all the way to the right! Be honest with yourself, and give yourself a 5 only when you truly think you would never forget it ever again.