The whip is used to encourage the horse to speed up. Whips, however, are rarely used in most polo matches since the rider must hold on to a mallet while riding, leaving little place for another weapon. However, some skilled riders may use their whip during freestyle polo. Polo was first played in Argentina in 1887. The first international match was held between England and Argentina in 1889. Although it is believed that the mallet used in these early games was a rubber ball, it is known that leather balls were used instead. In 1892, the British government approved funding for the development of an official ball for use in international matches. This ball, which is still in use today, is made from sheep's skin with a pig's bladder inside it. There are two types of shots in polo: shooting and passing. When shooting, the player uses only his or her hand and arm to strike the ball. Shots are taken by swinging the mallet back and then forward so that it hits the ground before rising again. The more powerful the stroke, the farther the ball will go. There are several techniques for striking the ball; for example, one can use either the flat side or the curved side of the mallet when hitting it. When passing, a player uses both hands to pass the ball to a teammate.