Like football leagues based on score.
OR
Something which breaks all the races up by the number of races they have done.
League 1 = Drivers over 1000 races
League 2 - Drivers between 500 - 999 races
etc. I say this as the guys at the top are pretty much never going to be caught up by mere mortals like me, so it would be good to know i am the best in my class, rather than being compared to played who have been racing for years.