If you are speed dominant, it will be hard to tell the difference. If you are rev dominant, the difference is obvious! I am rev dominant and consistently throw the ball in the 13mph range because of my age and injuries. The pin up ball will go longer an hit later. The pin down ball will tend to read earlier and sometimes flip, depending on the core.(especially if its asymmetric) But its hit will be just a little less on the backend.
Because of that lesser hit, I tend to have a lot of my weak balls used on dry and short patterns, pin down! I just throw them harder. But I have balls drilled pin down that I use in houses with very soft or weak backends that work also, because I want the ball to read earlier.
