A cup-and-ball consists of a small ball (usually made of wood) connected to the handle of the cup by a string of 35 to 40 centimeters. The cup is shaped to fit the ball. The player must not use any body part other than their handle-holding arm to catch the ball. The player must not purposefully bounce the ball off their body to change its trajectory. The main goal of the game is to get the ball into the cup. While the concept is very easy, mastering the game sometimes requires many hours of practice. The player tosses the ball upward by jerking the arm holding the toy, attempting to catch the ball in the cup. Cup-and-ball (or ball in a cup) is a traditional children's toy consisting of a wooden cup with a handle, and a ball attached to the cup by a string. It is popular in Spanish-speaking countries, where it is called "boliche". The name varies across many countries.