Bowling is one of the most popular sports in the world. One of the reasons for its popularity is its adaptability: children and adults of nearly every ability level can participate, and it can be enjoyed as leisure, recreational, and social activity or as a competitive opportunity. Children too young to execute a full approach can stand near the foul line and, using two hands, gleefully shove the ball down the lane. Teenagers, middle-aged people, even octogenarians frequent the lanes. Bowling leagues abound. No other sport in the world has such a diversity of participants.