Originally Posted by mbm0912
I've wondered the same. I'd say my hands are average. I'm currently going off the same rule with the finger you are referring to. If anything, I've considered going larger, to help minimize racquet turn in my hand.
I always used a 4 and 5/8 grip, but then found the 4 and 1/2 more comfortable and maneuverable, now that I am in my 60's and had a shoulder injury, I find the 4 and 3/8 better as it seems to make the racquet easier to swing, especially on serves, at least for me.