Can Somebody Please Explain The Stakes Grading System...

[docicu3]

I have tried to research this myself with numerous sites and history books but fail to see a consistency to the pattern of what makes a Grade 1 race different from a Grade 2 race etc....

I think I get the points idea for the Derby but what determines how much a given stakes race is worth and what category is goes in.

Maybe I just don't have the right reference material.....