Those medal can be reliated with your amount of PP (the PP system). It can make the game a bit more competitive? Also, maybe a season system?
Trainee: Between (top 100 000 to 50 000)
Beginners: Between (top 50 000 to 10 000)
Improved: Between (top 10 000 to 5000)
Increased: Between (top 5000 to 1000)
Advenced: Between (top 1000 to 500)
Challenger: Between (top 500 to 100 )
Pro: Between (top 100 to 10 )
Champions: Between (top 10 to 1)