The ranked list of all online players is available from the "CT players" item on the top level Playing menu. You can search for users by username (substring search), rating range , and activity level. Activity level is defined by the user's RD, the lower the RD, the higher their activity level. Activity level filtering applies to the most active rating in any of the rating types the user has played games in. The player list can be sorted by clicking on the relevant table headings.