The Driver Ranking at Driver Database uses the Elo rating system as its foundation.
Over 20,000 race results form the basis of the calculations. The rating is based on the average rating for the driver's last 20 races. Each driver starts out with a rating of 1500. The Driver Ranking is 100% objective as the championships are not ranked or graded, it's all maths.
Beating a driver with a higher rating will see a bigger increase in rating points than beating a driver with a lower rating. DNF's is skipped in the calculations as it is not always possible to find out reasons for them for all series.
For races where drivers share cars the average rating of the car's drivers is used for the calculations, instead of the driver's individual rating.
The ranking is updated once a week from the series we cover (see which series here).