Grip Size help needed

[poncho]

I currently use a grip size of 4 5/8 and play with the Ncode 90. I recently borrowed an K90 racquet with a grip size of 4 3/8 and put on 2 overgrips. I found that I seem to server better. I do not know if it is the racquet or the smaller grip.

Would the 2 overgrips give me a grip of 4 5/8 or would it be slightly smaller?

Do you suggest I get 4 1/2 and use one overgrip and would that give me a slightly smaller grip than 4 5/8?

I did the grip test and I can put in one finger between by thumb like the TW website suggests but I was wondering if most of you follow that advise and do you use a smaller grip size to serve better?

 

[fgs]

poncho,
that rule with the finger to fit between thumb ... is a "rule of thumb", i mean a general guideline which is basically valid.
applying two overgrips (of the thinner variety) would increase gripsize with 1/8, that is one size.
grip size changes the geometry, the way you hold the racquet. it is not uncommon to go for a slightly smaller gripsize for serves and topspin groundstrokes. a much too small grips size as well as a much too big one will in the long term give you some arm troubles, from soreness to way more critical issues as tenniselbow.
two overgrips would soften the feeling way too much, but that is again a matter of personal preference. i play with plain leather grips with no overgrip, and if you don't mind blisters and later on callouses, than that could be o.k., but once again - that is a matter of personal preference.
i haven't played the k90 yet, but taking from other threads it seems to be somewhat different than the n90. therefore it is possible that it is a combined effect of gripsize (changed geometry) and different racquet.