Legal and illegal in golf ball terms is whether your golf abides the United States Golf club association or Royal and Ancient Golf club of St Andrews. The united states golf club association, for instance, was formed in 1894 and since then they have been defining the standards of golf balls till today. According to (USGA), the golf ball should abide by certain weight and size below or above which it is illegal. Almost all clubs across the globe follow these regulations while procuring golf balls for their clubs. The most popular golf ball manufacturers like Callaway, Adidas and Percepts make sure that the golf balls they produce is according the USGA specification. In fact, these brands update and upgrade the golf ball specification every time they introduce a new innovation on golf balls to the public. And most professional golfers are aware of these specifications.