How to change your strike zone

[DaveASA/FED]

I have been told by a couple of UIC's that I need to raise my strike zone some. They recommend me movign it up about 2 inches. Described as me calling the ball touching the bottom of the knee cap, they want me to call the top of the knee. I respect these UIC's and if they think I am low I believe them, but I am really struggling in changing something that has become natural to me. I have only been doing this for about 6 years, so I am not "set in stone" but now I am questioning myself on every ball that is close to the knees. I feel like I am not consistant as I almost over analyze the low strikes. One suggested that I set up higher so the low pitch looks lower to me, but I find that screws with the top of my zone. Has anyone fought this before, or have any ideas how to "retrain" or adjust your zone? One of these UIC's is going to be my UIC for my first National in August so I know the bottom of my zone will be watched!