my yonex swing power racquet has grip size labeled as g4.5. is this common? is it smaller than G4? do you prefer g4 or g3?
You actually mean 4.5 "four point five"? I've never actually heard of Yonex making .5 differences as far as the grip goes. As far as the size relativity, the larger the G, the smaller the grip. Thus, G5 is smaller than G4. Generally I prefer smaller grips-- more room to maneuver. If it's too small, I can add more overgrips. But if it's too big in the first place, that's a problem.
yes, swing power is the only model that offer "4 and a half" grip size from yonex it means it is smaller than G4, but larger than G5 G1 being largest, G6 being smallest(as of yet, ns6k has it)
Does the G rating of a grip represent the thickness of the grip or the actual length of the grip handle before the cone? I'm confused because my Yonex Isometric 75 MF Light is rated G3 and has a shorter grip handle than my Yonex Armortec 800 Offensive which is rated G4.
Neither, it measures the circumference of the grip. The racquet wooden hold (handle) and its grip are carefully chosen to give you the right size and the most optimal feel of the 8-sided grip/handle. Using an overgrip changes the shape of this optimal feel, because the two flat sides will become narrower and the 4 bevels can now be hardly felt let alone made use of. So will replacing it with a thicker grip. Choose your racquet grip wisely. If not you will be forced to use overgrips and thicker replacement grips, which will change your grip to a rounder grip which is not optimal for grip and power. It will also make your racquet heavier and it may also affect repulsion power.
my size do you know how to accurately choose the right grip size? from the base of my palm to the top of my middle finger is 18 cm.
while the G-standard gives you an ideal how thick a grip is the size you actually prefer might be different than another person with a hand like yours trial and error is a good way