I figure I can just make my own ball rating matrix, for me. I get decent revs on the ball, speed isn't so hot. So for me, just about anything will hook. I mean, since I throw 14 - 16 mph, there is enough time down the lane for any ball to grip. So for me, everything will be hookable, but with minor adjustments up or down based on coverstock and drilling. And, both houses where I throw have reasonably dry backends, even in carrydown they are ok. Anything will work, but somethings might work a little better. I doubt that any ball I pick up out of any company would be totally unusable. I bowl on a house shot. Any ball works on a house shot. Even my white dot hooks, just carries a little worse.
I guess it is just a bit different for me, because I am a league bowler. All I do is bowl league. I don't have any delusions of grandeur. I might bowl a tourney, but really, my equipment is just for league. And truthfully, I've found that they all hook. They all hook plenty too. When I throw 4 balls that are supposed to look radically different on 1 pair of lanes, and they all give me a real similar shape, I can be pretty sure that any of them will do. I guess that my conclusion is that I am not at the level where I can appreciate the subtle differences in ball composition. I think most people can't. They just buy stuff because of what it is supposed to do. I know I did.
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I bowl at country club bowl...not a very inventive name now is it.