The rule of thumb is to be able to stick a finger between your fingers and thumb when you hold a racquet, which puts me at 4 5/8. . . but for many years I used a 4 1/2. So do you go with what the rule is, or is there a value in going with a bit smaller grip? I know the 4 5/8ths helps with my groundstrokes, but is the smaller size better for other purposes?