ADR stands for Average Damage per Round in CS:GO. It is the average amount of damage points dealt per round across an entire game, series, or event. A higher ADR means that a player has dealt more damage to their opponents in an average round, indicating a better performance. A good ADR ranges from 60 to 80, but most professional players have an ADR of 80 or higher. However, some superstar players can reach above 100 ADR. A low ADR indicates that a player needs to improve their gameplay. A players ADR can be checked during the game by pressing the "Tab" key to open the scoreboard, right-clicking to bring up the mouse cursor, and then clicking on the diagram icon at the top-right to see advanced stats.