The Annualized Excess Return/Standard Deviation graph measures the manager's excess returns (vertical axis) against standard deviation of excess returns or tracking error (horizontal axis). These are the two statistics used to compute the information ratio (excess return / standard deviation of excess return). This can be displayed for one computation or for rolling windows. With a rolling window each symbol represents a specified time period ( two year, three year, five year etc.) You have the option of showing excess return over the style or market benchmark. This graph is particularly useful when comparing multiple managers. It is also helpful in detecting structural changes in the portfolio. (A risk control process that was initiated several years ago would probably lower the portfolio's tracking error. As a result, the symbols would shift to the left).