| First thing is to look at the "Lane Condition" rating. BBI system first looks for the intended type of lane conditions(s) for a particular ball. Then, that ball's "Performance Ratings" are given. Here's a sample difference:
A 'Med-Short' length rating on Medium Oily/Oily lane conditions is NOT the same as a 'Med-Short" rating on Medium/Med-Oily lane condtions. Medium Oily/Oily balls hook earlier than Medium/Med-Oily balls.
Remember, always look for a ball's "Lane Condition" rating first when doing a "Side-by-Side Comparion." | 
