Each Driver has five stats:

• Overtaking - determines how many overtaking opportunities a driver sees and improves the overtaking chances.
• Defending - determines how effectively a driver will defend against overtakes and improves the defending chances.
• Qualifying - Improves the performance of your driver during qualifying sessions, allowing them to secure a better starting position on the grid. 
• Tyre Management - a high tire management stat will reduce your tyre wear in races.
• Race Start - A higher Race Start stat will give a boost to your Overtaking and Defending stats for the first lap of the race.