Did you know that your typical baseball used in the Major League has to adhere to strict manufacturing and performance guidelines? Everything must be standard, from the materials used to the mass of the ball -- even the number of stitches on the ball! Another measurement of the baseball, the Coefficient of Restitution, must also be standard. This measurement, also called the COR, is a measure of elasticity. A baseball has a COR of about 0.546, whereas a bouncy superball has a COR of about 0.9. Learn more about the COR, including how you can calculate it yourself.