gives a better idea of the "star rating" balls
5 balls : can be A+ , A or A-
4 balls : can be B+ , B or B-
3 balls : can be C+ , C or C-
2 balls : can be D+ , D or D-
etc ...
A player with A+ will be in the higher range of the 5 ball rating while A- will be in the lower range of 5 ball rating