As far as numbers go RG to me is one to the most important numbers. This gives me a feel for length and the general shape of the shot for that ball.
I then look at coverstock type. Heavy load particle, light load particle, resin, and whether they are pearlized or not.
And finally manufacture, manufactures do have tendencies for the hook shape of their balls, and I will pick the one that fits the shot shape I’m looking for. Skid/Flip I’ll look at Columbia, Track, Storm. ARC I’m looking at Brunswick or Ebonite.