It is an indication of how close a user's current rating is expected to be to Dragon's Go rank. When a new user enters an initial Go rank, Dragon does not know how well that initial value relates to Dragon's rank. World-wide-valid definitions of Go ranks do not exist. Dragon does its best to provide reliable and comparable Go ratings. On a user's rating graph the width of the blue background, which is similar to a confidence interval, estimates how close a new user's Dragon rating might be to Go ranks established by Dragon. The confidence intervals of both players in a game have an effect. A larger confidence width of one player increases rating change for that player and at the same time decreases rating change of the other player (and vice versa).