Lets say 3 categories with all hits in each category retrieved.
So the category with the most Hits would be given a score of 10 and all others would be given a lower score--
cars (7) (score: 10)
boats (6) (score: 9)
bikes (5) (score: 8)
Of course, the hits are constanly moving upwards so the top number would always be score of 10.
Is this even possible?