I use a 4 1/2 grip because I go by the old rule that says while gripping the racquet, you should be able to fit 1 finger in the remaining space between your thumb pad and finger tips. I wear a "large" size Men's glove, but I don't think I have unusually large hands. I just wonder why I seem to be in the minority of people that use anything larger than 3/8? Is there a benefit to going down to a 3/8 when your proper gripsize shows 4 1/2? Does it allow you to hold the racquet looser? Maybe get more wrist action on serves? I just never understood why 4 1/2 is such a rarely seen gripsize when I know there are many guys with hands at least as big as mine?