Proper Kickball Inflation
The Official GKB kickball is a red, 10", 3-ply, cross-textured rubber ball, customized with the GO Kickball insignia on front and back. In order to maintain consistency, it is important to use the official kickball for all games, and to inflate properly. The kickball should not be filled with so much air that it's hard like a basketball or softball, but rather a kickball should have a small amount of gripability to it. Do not overinflate! Overinflated kickballs have a tendency to lose their shape and "egg" after only a few uses, thus ruining the ball.
GKB corporate will provide you with a 31 inch diameter Inflation Rope to use as a guide when inflating kickballs, to ensure against over-inflation. Simply place the rope along the seam of the kickball while you're pumping it up. Stop pumping when the Inflation Rope is taut against the kickball, indicating that you've reached the proper diameter of 31 inches. (10 inches x Pi 3.14 = 31 inches.)
Note that after a kickball has been used and kicked around for a few games, the rubber will lose some of it's strength, and you'll need to pump more air into it in order to maintain full inflation. For this reason, moderately used kickball will naturally be slightly larger than a new one. The difference is most noticable when you pump up a brand new ball, which will appear smaller by comparison. Do not be fooled by the illusion and accidentally overinflate a new kickball. Use the Inflation Rope as a guide and you'll be good to go.